IMAP settings · proton.me · protonmail.com
Proton Mail IMAP settings
Proton Mail has no IMAP server you can connect to from the outside, and that is not an oversight: mail is stored encrypted, and only your own device holds the key. Access for mail clients goes through Proton Mail Bridge — a desktop application that decrypts locally and serves IMAP at 127.0.0.1, on your own machine. Which is why an online migration service cannot reach a Proton mailbox at all, ours included.
IMAP connection
- Server
- 127.0.0.1
- Port
- 1143
- Encryption
- STARTTLS
- Username
- full address
- Password
- the password from Bridge
Sending, SMTP
- Server
- 127.0.0.1
- Port
- 1025
- Encryption
- STARTTLS
Checked against the service's own autoconfiguration file on 2026-09-15 — the same source Thunderbird reads when it fills the settings in for you. Source: autoconfig.protonmail.com
What breaks here.
- There is no public hostname. The address a client connects to is 127.0.0.1 — your own computer — port 1143 with STARTTLS, served by Bridge.
- Bridge requires a paid Proton plan. On the free plan no mail client can connect, and nothing in the settings changes that.
- Bridge has to be running during the whole migration. Close it and the connection dies mid-transfer.
- The password is the one Bridge shows you, not your Proton account password.
Questions
The short answers
Can MoveMailbox migrate a Proton mailbox online?
No, and neither can any other hosted service. Bridge listens on 127.0.0.1, which only your own machine can reach. Use the desktop client on the same computer where Bridge runs — that works.
Is there any way without a paid plan?
Not over IMAP. The free plan has no Bridge, so a mail client cannot connect at all; exporting through the web interface is the remaining route.
Which port does Bridge use?
IMAP on 1143 and SMTP on 1025, both with STARTTLS, both on 127.0.0.1. Bridge shows the exact values, including the generated password.
Can I migrate into Proton instead?
Same rule in reverse: the destination has to be reachable, so it works with Bridge running locally and our desktop client on that machine.
IMAP settings
Settings for similar services
imap.ukr.net@UKR.NETIMAP access for a @UKR.NET mailbox: imap.ukr.net, port 993, SSL. Why the account password is rejected and where the app password comes from.imap.gmx.netGMXIMAP for a GMX mailbox: imap.gmx.net, port 993, SSL. Why access is off by default and when the host is imap.gmx.com instead.imap.web.deWEB.DEIMAP for a WEB.DE mailbox: imap.web.de, port 993, SSL. Access has to be enabled by hand, and the username goes in without @web.de.imap.mail.commail.comIMAP for a mail.com mailbox: imap.mail.com, port 993, SSL. Access for external programs is a setting in the mailbox, not a default.imap.wp.plPoczta WPIMAP for a wp.pl mailbox: imap.wp.pl, port 993, SSL. The username goes in without @wp.pl, which is where most setups fail.imap.aol.comAOL MailIMAP for AOL Mail: imap.aol.com, port 993, SSL. Why the account password is refused, and the separate export host for downloading a whole mailbox.imap.fastmail.comFastmailIMAP for Fastmail: imap.fastmail.com, port 993, SSL. Every client needs its own app password, and the Basic plan has no IMAP at all.Find out how big your mailbox is. It costs nothing.
Connect two servers, look at the size and decide. Or take the client and keep everything on your side.
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