Let's Encrypt & ZeroSSL certificates don't work for pop/smtp/ftp.domain.com but work for everything else.

[Richard G]

I added "TLSOption IgnoreSNI"

Did you make a typo or did you really put it in like this? Because it should be:
TLSOptions IgnoreSNI
with an s at the end of options. If it is like that, then I don't know anymore. Maybe somebody else because I know there are people using proFTPD with FTPS.

 

[Panormitis]

Yes I added it like this TLSOptions IgnoreSNI
The typo was in the forum post only. Perhaps additional options are needed.