Problem sending mail

I am able to receive incoming mail from mypostoffice account but not able to send mail.
The “From” label on the send screen shows “no account”.
Robert Briggs

Hello,

please look in Tools - Accounts - your account if there is SMTP tab and if yes then look in it and write me Port and security policy

regards
Jan

Thank you Jan
Tool - Accounts takes me to IMAP screen which shows
Host: imap.mypostoffice.co.uk
Security Policy: Use SSL/TLS if available
Any advice to make this work would be much appreciated.
Robert

Hello,

I need that port number as sometimes old ports are used and are not compatible with modern security policy.

regards
Jan

Port Number is 143

Regards
Robert

Hello,

really 143? are you looking in IMAP or SMTP? Is SMTP tab even in your account settings?

regards
Jan