The Proton Mail SMTP, IMAP and POP3 settings you need — server 127.0.0.1, port 1025 (STARTTLS). Copy each field with one click. Free, with no signup.
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Proton Mail mail settings
Outgoing mail (SMTP)
SMTP server
127.0.0.1
Port — STARTTLS
1025
Security
STARTTLS on 127.0.0.1:1025, provided locally by Proton Mail Bridge.
Incoming mail (IMAP)
IMAP server
127.0.0.1
Port — STARTTLS
1143
Incoming mail (POP3)
POP3
Not supported by this provider.
Sending limits & login
Daily send limit
Send limits apply per plan (Proton throttles to prevent abuse).
Authentication
Third-party SMTP/IMAP needs Proton Mail Bridge (paid plans) running on your machine — it exposes a local, encrypted gateway.
App password
Use the username and password that Proton Mail Bridge generates, not your Proton account password.
Proton encrypts mailboxes end-to-end, so external clients connect through the local Bridge app rather than to Proton's servers directly.
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Try EmailChaser freeFind the SMTP, IMAP and POP3 server settings for any email provider. Free, with no signup — every field copies with one click.
To send email through Proton Mail, set your outgoing (SMTP) server to 127.0.0.1 and use port 1025 (STARTTLS). STARTTLS on 127.0.0.1:1025, provided locally by Proton Mail Bridge.
For incoming mail, use the IMAP server 127.0.0.1 on port 1143. Pick the exact values from the tool above and copy them straight into your mail client.
Send limits apply per plan (Proton throttles to prevent abuse). Third-party SMTP/IMAP needs Proton Mail Bridge (paid plans) running on your machine — it exposes a local, encrypted gateway. Use the username and password that Proton Mail Bridge generates, not your Proton account password.
Those caps make single-mailbox sending fine for personal mail but a poor fit for cold outreach at volume. Emailchaser spreads sending across warmed inboxes and manages deliverability, so you can scale without burning Proton Mail accounts.
What are Proton Mail's SMTP settings?
Proton Mail's outgoing (SMTP) server is 127.0.0.1. Use port 1025 (STARTTLS). STARTTLS on 127.0.0.1:1025, provided locally by Proton Mail Bridge. Sign in with your full email address and password (or app password).
What is Proton Mail's IMAP or POP3 server?
Proton Mail's incoming IMAP server is 127.0.0.1 on port 1143 (STARTTLS). POP3 is not supported.
Which port should I use for Proton Mail?
Use port 587 with STARTTLS wherever it's offered — it's the modern standard for authenticated sending. Port 465 with SSL/TLS is a solid alternative. Avoid port 25, which most networks block for client sending. Proton Mail's recommended value is above.
Why won't my Proton Mail SMTP connection work?
Check authentication first: Third-party SMTP/IMAP needs Proton Mail Bridge (paid plans) running on your machine — it exposes a local, encrypted gateway. Use the username and password that Proton Mail Bridge generates, not your Proton account password. Then confirm the host, port and security method match exactly — a 587/SSL or 465/STARTTLS mismatch will fail to connect.
Can I send bulk or cold email through Proton Mail?
Not at scale. Send limits apply per plan (Proton throttles to prevent abuse). Providers throttle bursts to fight spam, so pushing cold email through one mailbox hits limits and wrecks deliverability. High-volume outreach belongs on dedicated infrastructure that spreads sending across warmed inboxes — which is what Emailchaser does.
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