anyone have this problem, any ideas to fix it?
I'll bet you can send no problem via the mobile network.... the mail account on your handset will be configured to use your carrier's SMTP server, but when on wifi you're using your ISP's network and most SMTP servers reject connections from outwith their own domain as a precaution against spam relay.
This thread in the Desire Z section discusses the issue and provides an elegant solution using GMail as an aggregator on your handset.
Try clicking your settings button, accounts, pick your email, touch outgoing server, touch advanced settings. Uncheck use secure connection and change the two drop down boxes to never and none and touch ok. This should fix your problems. May also have to do this after software upgrades.
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