Test a server!
You can test every type of server that talks TLS or StartTLS. You may e.g. enter:
- In the 'domain' field:
smtp://example.com:587
and leave the 'port' field empty - In the 'domain' field:
example.com
and in the 'port' fieldsmtp-587
- In the 'domain' field:
example.com
and in the 'port' fieldxmpp-server-5269
- In the 'domain' field:
example.com
and in the 'port' fieldxmpp-5222
- In the 'domain' field:
imap://example.com
and leave the 'port' field empty - In the 'domain' field:
example.com
and in the 'port' fieldimap-143
- ...or any plain TLS talking server/service