Most providers, in a misguided attempt to block bogus outgoing Email initiated by trojans infecting Windows systems, have started blocking Port 25 - the customary port used to send outgoing Email (SMTP). Almost every large ISP has made this change so you need to be aware that the default settings for your Email client will rarely work these days. The simple fix is to change your outgoing mail port from 25 to 587 which they do not block.
This is a common thing these days - we might be the only provider locally not blocking standard mail ports leaving their network.
If you need any help be sure to call our tech support at 783-3454.