Try STARTTLS Ports on imap and smtp when sending a mail fails

Mobile apps
1

I started with EM Client this week and was impressed by all the useful features.
Configured about 20 hosts which worked without a problem including the Testmail that is sent.
Most of them are different mail accounts for my domain.
This morning I sent my first mail and all of them started to fail.
Connection to SMTP failed and imap stopped working as well. Account was set offline.

Went into the config and found that the default non ssl ports were set.
Changed them to SSL/TLS imap 993 smtp 465 but still failed.
Finally tried the STARTTLS ports imap 143 smtp 587 and everything was working fine again.

As my other Mail apps Airmail and Apple Mail are working fine with SSL/TLS I assume, EM Client has specific problems to use SSL/TLS with my Webhoster.

Maybe others with similar issues might find my circumvention useful.
Regards … Franz

2

These are the IMAP & SMTP server ports and security policies you can normally use for secure connections on Desktop & Mobile which is different for V10.3 or higher than the older V6-10.2 further down at the end of this post.

eM Client V10.3 or higher

(IMAP)
Server Port - 993
Security Policy - "Use TLS on Special Port”

Or

Server Port - 143
Security Policy - "Use STARTTLS if available”

(SMTP)
Server Port - 587
Security Policy - "Use STARTTLS (Always)”

Or

Server Port - 465
Security Policy "Use TLS on Special Port”

—

eM Client V6 to V10.2

(IMAP)
Server Port - 993
Security Policy - “Use SSL/TLS on special port (legacy)”

Or

Server Port - 143
Security Policy - Use SSL/TLS if available

(SMTP)
Server Port - 587
Security Policy - “Force usage of SSL/TLS”

Or

Server Port - 465
Security Policy - “Use SSL/TLS on special port (legacy)”

3

I’m using iOS with latest version:10.5.308 (5117ba9).
Security Policy doesn’t offer "Use STARTTLS if available” or Use STARTTLS (Always)”

But ports 143 / 587 work as well with “Force usage of SSL/TLS”

4

Hello, we do not recommend using the legacy options if possible - “Force usage of SSL/TLS” should work here and will use STARTTLS at well, you can enable the logs and send them to our team for analysis if you want us to look into it.

SMTP logs can be enabled in Settings > the affected Account > scroll down and click SMTP > Enable diagnostic logs.
Then replicate the issue and send the log files to [email protected]