Cannot send MobileMe mail from Mail in Lion
I installed Lion the day after it came out, and had no problems initially. 3 days ago, however, Mail stopped being able to send messages from my MobileMe account. Every time I try to send a message, I get the following error:
Any idea what could be causing this? I can receive mail fine, and I have no problems sending if I use the MobileMe web interface. It is only through the Mail application that I cannot send. This is very inconvenient, and I'd be grateful for any help anyone can provide. Thank you!
Mac Pro, Mac OS X (10.7)