email works but says invalid email when registering on....

[Necrotic]

My email system is working great! But....When I try to register for online forums or try to buy products online using my roundcube email address I AWAYS get an error from those sites saying "Invalid Email Address". Does anyone know why I would be getting those messages?

[rosali]

This is definitely no Roundcube issue.

[Necrotic]

Great. Thanks.