SMTP sending limits for 51 email providers
What each provider says one account can send through SMTP: per day, per hour, recipients per message and the largest attachment. Every cell is the provider's own published figure, printed as the provider states it, with a link to the page it came from. Where a provider publishes nothing, the cell says "not published" rather than a guess.
25 of 51 providers publish a daily limit, 12 an hourly one, 27 a recipients-per-message cap and 45 an attachment size. Confidence is how clearly the provider documents the figure: high for 33 providers, medium for 17, low for 1. 51 of 51 rows link to a source. Limits change, so check the source before relying on a number.
Consumer email providers (20)
| Provider | Per day | Per hour | Recipients per message | Attachment max | Confidence | Source |
|---|---|---|---|---|---|---|
| Gmail Go past either 500 and Gmail blocks further sending for 1 to 24 hours before it clears on its own. | 500 messages | not published | 500 recipients | 25 MB | high | support.google.com |
| Outlook.com A separate cap of 1,000 daily non-relationship recipients applies to people you have never emailed before, and new accounts start lower until they build history. | 5,000 recipients a day for Microsoft 365 subscribers, lower for free accounts | not published | 500 recipients | 25 MB for the whole message, text and files together, or up to 2 GB per file when sent as a OneDrive link | medium | support.microsoft.com |
| Yahoo Mail Yahoo states it does not disclose how many recipients or messages you can send at once, in order to enforce anti-spam rules; when you hit a limit the notice usually says how long to wait. | not published | not published | not published | 25 MB of attachments per message, applied to both incoming and outgoing mail | high | help.yahoo.com |
| iCloud Mail Apple describes iCloud Mail as a personal service and prohibits unsolicited bulk sending; exceeding a limit produces a named alert rather than a silent drop. | 1,000 messages per day | not published | 500 recipients per message, and 1,000 recipients per day | 20 MB per message, or up to 5 GB with Mail Drop turned on | high | support.apple.com |
| AOL Mail AOL states it does not disclose the number of recipients or emails that can be sent at one time; when you are blocked, the notification generally tells you how long to wait. | not published | not published | not published | not published | medium | help.aol.com |
| Zoho Mail Counted on a rolling one-hour basis and adjusted by Zoho's servers according to your account's sending reputation, rather than as a fixed daily quota. | not published | 50 to 500 emails to outside addresses, 1,000 to colleagues in the same organisation | 150 external recipients on paid accounts, 100 on free accounts, 500 internal | 40 MB per incoming message, up to 500 attachments | high | zoho.com |
| GMX Mail GMX publishes attachment sizes per tariff but publishes no daily, hourly or per-message recipient figure anywhere in its own help centre. | not published | not published | not published | 20 MB on FreeMail, 50 MB on ProMail, 100 MB on TopMail | high | hilfe.gmx.net |
| WEB.DE WEB.DE states that a per-message recipient cap exists but describes it only as 'very high' and adjusted as needed by its spam protection team, and gives no daily or hourly number. | not published | not published | not published | 20 MB on FreeMail, up to 100 MB with WEB.DE Club or MailPlus | high | hilfe.web.de |
| T-Online Telekom's Homepage Center help states 100 emails per day per mailbox (1000 on the Business tiers), but that covers Homepage Center mailboxes rather than a plain @t-online.de mailbox, so it is not carried over here. The telekom.de pages that would confirm t-online.de figures redirect to a Telekom login and cannot be read. | not published | not published | not published | not published | low | homepagecenter.telekom.de |
| Mail.com mail.com's product page gives 30 MB for free accounts while its Premium help page says a free account may only be warned above 50 MB, so treat 30 MB as the safe free ceiling; no daily, hourly or recipient number is published, and external client access is Premium-only in any case. | not published | not published | not published | 30 MB on a free account, up to 100 MB on Premium | high | support.mail.com |
| Proton Mail Each recipient counts as a separate email, so one message to ten people uses ten of your allowance. | 150 emails on the free plan; paid plans vary with account reputation | 50 emails on the free plan | 100 recipients across To, CC and BCC | 25 MB total per outgoing email, across up to 100 files (50 MB incoming) | high | proton.me |
| Fastmail There is also a 10 minute cap set at half the hourly figure, plus a smaller unpublished cap on the number of distinct recipient addresses. | 4,000 messages on Basic, 8,000 on Individual, Duo, Family and Business Standard, 16,000 on Business Professional; 120 on trial accounts | Half the daily figure, so 4,000 on an 8,000 plan and 8,000 on Business Professional | not published | 70 MB total message size, which is roughly 50 MB of attachments after encoding | high | fastmail.help |
| mailbox.org The cap is not a plain counter: mailbox.org scores account age and recent volume, and accounts that spike suddenly can be blocked at roughly 5,000. | 10,000 emails on a regular private account; unpaid test accounts are capped at 10 | not published | not published | 100 MB per email | high | kb.mailbox.org |
| Posteo The hourly and daily figures come from Posteo's terms of service; before the first payment the account is held to 10 emails per two hours. Posteo's own pages disagree on attachments: the features page says 100 MB each way, while the terms of service still say 50 MB, so treat 50 MB as the safe number. | 1,000 emails | 500 emails | not published | 100 MB sending and 100 MB receiving | medium | posteo.de |
| Yandex Mail Limits count recipients in the To, Cc and Bcc fields. A block clears automatically after 24 hours if you stop trying to send, otherwise it is extended another 24 hours, and Yandex lowers the limits further if its anti-spam sees mass mailing of similar or promotional messages. | 500 recipients in any 24-hour period, counted as recipients rather than messages | not published | 35 in one email sent from a mail client or over SMTP and 50 from the site, per Yandex's 'I can't send emails' page; Yandex's 'Sending a large number of messages' page gives 300 from a client and 1,000 from the site for the same service, so treat 35 as the safe floor | Attachments over 25 MB are uploaded to Yandex Disk automatically and arrive as links; the maximum attachment size is 1 GB without a Yandex 360 plan, and a file added from Yandex Disk can be up to 10 GB | medium | yandex.com |
| Mail.ru Mail describes the sending cap only as a limit per hour without publishing the number, and the symptom of hitting it is the 'Ratelimit exceeded for mailbox' error. | not published | not published | 30 recipients in one message | Files over 25 MB are uploaded to Mail Cloud and arrive as links, which are deleted 180 days after receipt | medium | help.mail.ru |
| QQ Mail Total ordinary attachments sent in one day are capped at 200 MB; Tencent publishes no daily message count. | not published | not published | No fixed number; Tencent says the cap tightens or loosens according to its anti-spam scoring | 50 MB per ordinary attachment, and 55 MB for message body plus attachments | high | help.mail.qq.com |
| 163 Mail (NetEase) Going over a limit blocks sending until the system clears it, normally within 24 hours; membership raises limits for the web mailbox and Mail Master only. | About 300 to 400 messages on a free account, 700 to 800 on basic membership, 1,300 to 1,400 on super membership | not published | 50 per message on a free account, 200 for members | Files over 50 MB are pushed into NetEase's cloud attachment route, which takes up to 3 GB per file for free accounts | medium | help.mail.163.com |
| Naver Mail Naver deliberately keeps its daily send cap secret; crossing it can take up to 24 hours to clear, and messages carrying large files are limited to 10 sends a day. | not published | not published | 100 addresses per message, counting To, Cc and Bcc together | 10 MB per ordinary attached file; anything larger becomes a large file, up to 2 GB each and 10 per message | high | help.naver.com |
| Libero Mail Libero sets sending thresholds case by case rather than publishing a daily figure, and can expire the password instead of bouncing the mail; anything over 25 MB is pushed into DriveMail, which takes up to 2 GB. | not published | not published | 50, counting To, CC and BCC together | 25 MB per outgoing message | high | aiuto.libero.it |
Internet provider (ISP) email (8)
| Provider | Per day | Per hour | Recipients per message | Attachment max | Confidence | Source |
|---|---|---|---|---|---|---|
| Comcast Xfinity Comcast counts recipients rather than messages, and the mailbox itself stops accepting new mail once it reaches 10 GB of storage. | 1,000 recipients per day | not published | 100 recipients per message | 25 MB total message size, including headers and formatting | medium | xfinity.com |
| AT&T Mail AT&T Mail accounts come with 1 TB of mailbox storage, but AT&T's help centre publishes no daily send or per-message recipient cap. | not published | not published | not published | 25 MB total message size, across a maximum of 50 attached files | high | att.com |
| Spectrum Spectrum says it also caps how many messages an account can send per hour but does not publish that number. | 1,000 recipients per 24 hours, or 100 messages per 24 hours if the account is less than a week old | not published | 99 recipients per message, counting To, Cc and Bcc together | 30 MB per message, 20 MB per individual attachment | medium | spectrum.net |
| Cox cox.net mailboxes run on Yahoo Mail now, and Yahoo states it does not disclose how many recipients or messages can be sent at one time. | not published | not published | not published | 25 MB of attachments per message, the Yahoo Mail limit that now governs cox.net | medium | cox.com |
| BT Internet BT does not publish its send limits; hitting one returns error 452 or 0781, and BT's advice is to split the list and slow down. | not published | not published | not published | not published | high | bt.com |
| Sky Sky states it does not disclose how many recipients or emails you can send at once; when you trip a limit the notification tells you how long to wait. | not published | not published | not published | 25 MB total per message, incoming and outgoing | medium | uk.help.yahoo.com |
| Orange Orange publishes no per hour or per day sending figures; only the message size ceiling is stated. | not published | not published | not published | 25 MB per email, 30 MB with the Gigamail option | high | assistance.orange.fr |
| Telstra Storage is 10 GB per address, and both sending and receiving stop once the mailbox goes over it. | not published | not published | not published | 25 MB per message including attachments | high | telstra.com.au |
Business email and web hosting (12)
| Provider | Per day | Per hour | Recipients per message | Attachment max | Confidence | Source |
|---|---|---|---|---|---|---|
| Google Workspace External recipients are capped separately at 3,000 a day. The SMTP relay service is counted on its own, at 10,000 messages per user per 24 hours and 4.6 million recipients per organization per 24 hours. | 2,000 messages per user, 1,500 for mail merge, 500 on a trial account | not published | 100 recipients per message when a POP or IMAP user sends through SMTP, against 2,000 per message from the Gmail interface | 25 MB on Business, Education and Enterprise Standard, up to 50 MB on Enterprise Plus in the web interface | high | knowledge.workspace.google.com |
| Microsoft 365 SMTP client submission is also capped at 30 messages per minute, and anything over that is throttled and carried into the following minutes rather than blocking the account. A separate tenant-wide external recipient limit applies, sized by how many licences you hold, and is shown in the Exchange admin center mail flow reports. | 10,000 recipients per mailbox per day | not published | Customisable by the admin between 1 and 1,000 recipients | 35 MB default maximum send size per message, 36 MB to receive, and an admin can set anything from 1 MB to 150 MB | high | learn.microsoft.com |
| GoDaddy Limits are set by the product you bought, not by GoDaddy centrally: Microsoft 365 from GoDaddy adds a 30 messages per minute ceiling, and GoDaddy web hosting has its own separate relay limit. | 500 messages per mailbox per day over SMTP and 1,500 via webmail on Professional Email; 10,000 messages per 24 hours on Microsoft 365 from GoDaddy | not published | 100 addresses across To, Cc and Bcc on Professional Email; 500 on Microsoft 365 from GoDaddy | 30 MB total message size on Professional Email; 35 MB sent and 36 MB received on Microsoft 365 from GoDaddy | high | godaddy.com |
| Namecheap Private Email Everything is metered per domain rather than per mailbox, and a separate 2 GB per hour outgoing traffic quota can throttle sending before the message count is reached. MIME encoding inflates an attachment by roughly 40%, so a 35 MB file already fills the 50 MB message ceiling. | not published | 500 emails per hour per domain on Starter, 1,000 on Pro, 1,500 on Ultimate; 500 on the legacy Private, Business and Business Office plans; 50 on trial plans | 50 across To, Cc and Bcc | 50 MB maximum outgoing message; 25 MB for a single file uploaded in webmail | high | namecheap.com |
| Rackspace Email The daily cap counts recipients rather than messages and resets at midnight US Eastern; receiving is separately throttled to 400 messages per mailbox per 10 minutes. | 10,000 recipients per email address per 24 hours | not published | not published | 50 MB per message including headers, body and attachments | high | docs.rackspace.com |
| IONOS The hourly rate rises with the age of the mailbox; storage is 2 GB or 100,000 emails on Mail Basic and 50 GB or 500,000 emails on Mail Business, and a full mailbox stops accepting incoming mail. IONOS-hosted Exchange is metered differently again, at 1 to 10 emails a minute over IMAP/POP3 by mailbox age. | not published | 50 emails an hour in the first 7 days, 100 to day 14, 400 to day 30, then 500 (Mail Basic and Mail Business) | not published | 70 MB per attachment on Mail Basic and Mail Business; 100 MB on IONOS-hosted Microsoft Exchange | medium | ionos.com |
| Hostinger Counted per mailbox over a rolling 24 hours, with sent and received counted separately. | 1000 sent per mailbox on Business Starter, 3000 on Business Premium, 100 on free and trial plans | not published | 100 across To, Cc and Bcc | 25 MB of attachments, 35 MB total outgoing message size | high | hostinger.com |
| Titan Email Hourly caps scale with the plan and reset at the top of the next hour. | not published | 50 to 500 messages to outside addresses depending on plan, and around 1000 an hour to addresses on your own domain | not published | 30 MB for all attachments on one message combined | medium | support.titan.email |
| Bluehost The hourly cap is counted per domain, so addon domains and subdomains each get their own allowance. | not published | 500 outgoing per domain on shared hosting, no set cap on VPS and dedicated | not published | 50 MB hard limit, 35 MB recommended | medium | bluehost.com |
| HostGator The cap is per domain, including addon domains and subdomains, and mailing lists over 900 addresses may only go out at weekends or between 1am and 8am Eastern on weekdays. | not published | 500 outgoing per domain on shared and reseller plans, unlimited on VPS and dedicated | not published | not published | high | hostgator.com |
| SiteGround Limits are set per site, and a message over the recipient count is refused with a Too many recipients error rather than being queued. | not published | 400 on StartUp, GrowBig, Ecommerce and Coderick, 800 on GoGeek and Cloud | 40 per message, 80 on GoGeek | 50 MB of attachments outgoing, 80 MB incoming | medium | siteground.com |
| cPanel Hosting cPanel sets no sending limit of its own; the hosting company configures the caps on the server, which is why the same panel allows 500 an hour at one host and a different number at another. | not published | not published | not published | not published | high | docs.cpanel.net |
SMTP sending services (11)
| Provider | Per day | Per hour | Recipients per message | Attachment max | Confidence | Source |
|---|---|---|---|---|---|---|
| Amazon SES Quotas are counted per recipient and are set separately for each AWS region; the sandbox also caps you at 1 message per second. | 200 messages per 24 hours in the sandbox; raised on request once in production | not published | 50 recipients per message, counting To, Cc and Bcc together | 40 MB per message including attachments, measured after base64 encoding, when sending over SMTP | high | docs.aws.amazon.com |
| SendGrid Paid plans are metered by monthly volume rather than a daily cap; SMTP separately allows 5,000 messages per connection and 10,000 concurrent connections from one server. | 100 messages a day during the 60 day trial | not published | 1,000 across To, Cc and Bcc (documented for the Mail Send API) | 30 MB total message size including attachments (documented for the Mail Send API) | medium | twilio.com |
| Mailgun Paid plans are metered by monthly volume (10,000 on Basic, 50,000 on Foundation, 100,000 on Scale) rather than a daily cap. | 100 emails a day on the free plan | not published | 1,000 recipients per batch send | 25 MB total message size including attachments | medium | documentation.mailgun.com |
| Postmark Postmark asks customers to keep to 10 concurrent SMTP connections per IP and says it does not enforce that in software; the text and HTML bodies are separately capped at 5 MB each. | No published daily cap | not published | 50 recipients per message, counting To, Cc and Bcc together | 10 MB total message size including attachments, measured after base64 encoding | high | postmarkapp.com |
| Brevo The free plan's 300 resets every day and unused sends do not roll over. Once you hit the cap, up to 1,000 further emails are held in a retry queue and anything beyond that is not delivered | 300 emails a day on the free plan; Starter and above have no daily cap | not published | 99 recipients when the message carries an attachment | under 4 MB per attachment, 20 MB for the whole message including content | high | help.brevo.com |
| Mailjet The free plan is 6,000 a month with the 200 a day cap on top; overflow queues for 3 days and is then deleted | 200 emails a day on the free plan | not published | not published | 15 MB for the whole message including attachments, on every plan | high | dev.mailjet.com |
| SparkPost SparkPost asks for at most 100 messages per connection, drops idle connections after 1 minute, and expects a per-command timeout of at least 60 seconds | not published | not published | 1,000 in total across the cc, bcc and archive lists combined | not published | medium | developers.sparkpost.com |
| SMTP2GO Up to 40 simultaneous connections per IP and up to 5,000 emails on one connection. Free accounts are also capped at 25 an hour until the sender domain is verified | No fixed daily cap on paid plans; new accounts are held to 1,000 a day during an initial probation period | 200,000 emails an hour by default, raised on request | 400 per email, with 50 to 100 recommended | 50 MB for the whole email including attachments | high | developers.smtp2go.com |
| Elastic Email Paid plans set their own daily figure; concurrency is capped at 20 requests from one IP and a single SMTP command times out after 2 minutes | 100 emails a day on the free plan | not published | not published | 10 MB for the whole email; any number of files as long as they fit inside that | high | help.elasticemail.com |
| Resend Free plan is also capped at 3,000 a month, and the 10 requests a second rate limit is per team, shared across all API keys | 100 emails a day on the free plan | not published | 50 addresses in the To field | 40 MB per email, measured after base64 encoding | high | resend.com |
| Mandrill Anything over the hourly quota goes into a backlog and is deleted after 48 hours | not published | A moving quota Mailchimp calculates from your account reputation and your normal sending volume; it cannot be set manually | not published | 25 MB for the whole message, counted after base64 encoding | high | mailchimp.com |
What the limits mean for cold email
Every figure above is a cap on one mailbox. Hitting it on a new mailbox's first day is what gets that mailbox filtered, so the useful number for outreach is not the cap but how quickly you approach it. As of September 2026, Emailchaser's gradual build-up starts a connected mailbox at 5 emails a day in its first week and adds 5 a day each week, holding at 50 a day until you switch it off. How the ramp works.
Each provider name links to its own page with the server, ports, login details and setup steps. The SMTP Settings Finder covers all 51.