Mailspring using iCloud IMAP fails to deliver email sent

Service Issues
1

Running Apple OS 11.4. Fresh Install of Mailspring today (6/3).

As installed, using the set-up option of iCloud (IMAP) for user name and Apple-supplied password, the email client will receive email fine, but fails to deliver email to my other email accounts, vis-a-vis gmail and protonmail.

This is consistent, over the last few days, and occurs on my Linux Laptop running POP!_OS 20.04/Ubuntu 20.10 using the same configurations.

Any ideas?

2

For iCloud, make sure you’re using an app-specific password (not your Apple ID password). Generate one at appleid.apple.com > Sign-In and Security > App-Specific Passwords. Use:

  • IMAP: imap.mail.me.com, port 993, SSL
  • SMTP: smtp.mail.me.com, port 587, STARTTLS
  • Username: your iCloud email (e.g. yourname@icloud.com)
  • Password: the app-specific password you generated