Mail Merge testing account fails

Dear all,

I'm trying to set up sending emails with mail merge. I entered my
credentials etc. in Tools>Options>LibreOffice Writer>Mail Merge E-mail, but
when I hit "Test Settings", it hangs for a couple minutes and shows me the
following error. Same error with email accounts from several providers.
Is there a way I can fix this?

Many thanks!
Max

LibreOffice could not connect to the outgoing mail server. Check your
system's settings and the settings in LibreOffice. Check the server name,
the port and the secure connections settings

Hi Max

What version of LibreOffice are you using?

Have you checked your settings are correct?

When I change the settings I've found that the "Test Settings" can fail.

Closing down LibreOffice completely and restarting always seems to fix it for me.

Alex