Problems sending via smtp.simply.com

Make sure you have entered "smtp.simply.com" under the outgoing server, and that the host name is spelled correctly.

Always try using port 587 first for sending.

If you are using port 25, or any port other than 587 for sending, try port 587 instead.

Ensure you have ticked the box "Outgoing mail server requires authentication", which is often found under "advanced account settings" in your mail client.

Ensure there is NOT a tick in "Log on with secure password authentication".

Verify you are using the same login credentials for the outgoing server as for the incoming one. Also check that these details are entered correctly under the incoming server.

Check that antivirus and firewall programmes are not blocking the connection. Try temporarily disabling them to see if that helps.