SMTP test at account setup is incorrectly using IMAP address as "FROM"


When you first add an imap/smtp account to mailspring it has to successfully send an email through SMTP server to validate settings. Sure, fine.

It proceeds to log in using the SMTP details I provided and then tries to send an email as the email address in the IMAP details instead. I’m not sure why that’s a thing.

Mailspring should send MAIL FROM: <> or simply quit it at 235 Authentication successful. Instead it sends this:

235 Authentication successful MAIL 550 Unable to authenticate sender SMTP Last Response Code: 550 SMTP Last Response: Unable to authenticate sender

To Reproduce…

Steps to reproduce the behavior:

  1. install mailspring
  2. add an imap/smtp account with different authentication details – I also have different servers too because I’m trying to do what I outlined here )
  3. It will fail to add the account and if you view the log it will be similar to what I have above

Expected Behavior

mailspring should be satisfied by 235 Authentication successful , or at least not mix up imap/smtp details provided.


  • OS and Version: Windows 10
  • Mailspring Version: 1.7.6

Additional Context

See also, Make SMTP or IMAP optional (Read-only or Send-only accounts)

(Originally posted by working-name on GitHub.)