Emails won't send with SSL enabled from iPad

[#1]

Hello,

My wife's iPad has suddenly stopped sending emails.  I have checked the settings - all OK - and reinstalled Mail, to no avail. I can get it to send mail with SSL disabled, but  I'm worried that the emails will no longer be encrypted.  The outgoing port is 587 (I tried 465 but no go). The iPad is a Mini 4, IoS is up to date at 15.8.8.

Any help would be most appreciated.

Many thanks,

Dave 

[#2]

Which SMTP server are you using ?

[#3]

Thanks for your speedy response Philip.  I'm pretty dim when it comes to the workings of email; are you referring to the outgoing settings?  If so, that is set at relay.plus.net 

[#4]

SMTP ( out going ) server : relay.plus.net  does support encryption.

SSL/TLS via Port 465

STARTTLS via Port 587