Former Postbox user here, currently on the 30 day trial for eM client.
However I have a problem with setting up Protonmail SMTP. Yes, I am on the Mail plus plan, so I can use eMail clients and also have bridge installed. IMAP sync works fine but somehow I cannot send eMail via SMTP. I’ve used the exact settings from Bridge and also followed the steps from this thread:
As mentioned, while SMTP does not sync at all, IMAP works just fine so I am ruling out an issue with PM Bridge. Attached is the error message I am getting.
thank you @Heisenberg, I encounter the exact same issue and I am amazed that it has not been solved since nov 2024 when we are in march 2026… @support of eM Client: please help.
Hi, while we can’t tell for sure without more detailed logs or without seeing your settings, if you are getting the same error, VPN, firewall, and other security software is often the issue, and adding eM Client to the list of exclusions helps in those cases, so I recommend starting with that.
If you’d like to explore this more closely, I can see that you have VIP support active, so you can submit a ticket at https://support.emclient.com/, just note that me or my colleagues will likely ask you to test the above first anyway.
In any case, many of our users have Proton accounts configured without any issues. This would be an isolated case, not something that has been overlooked for years.
