SMTP not working for mail client, but Webmail sends ok

[Liquidream]

cPanel username: liquidre

Hi,
I've been trying on & off for ages to send mail via SMTP using my account (in mail clients), but it never works. Using the settings as per cPanel > Mail Accounts always results in a "Timeout error".
I've tried various clients (inc. Firebird) and varous machines (inc. Android phone) and get the same results.
Also, if I try via SSL I fails (eventually), but also get a security warning (which stops it working on Android full-stop).
Please could someone check to see if there is something wrong with my account.
I'm not an idiot, I develop software for a living, I've tried every combination possible, with a couple of accounts.
Something must be wrong here.

Many thanks,
Paul.

[Liquidream]

Anyone at all?