Can't send to a group

[dodger]

I have 250 email addresses in a group - when I try to send I get the
following error -

0x800ccc79 "501 illegal address syntax"

The error does not say which email address may be faulty and doesn't
send any of them - is there any way of finding out which address is
causing the problem?

Thanks.

 

[dodger]

I had to split the group till I found the offending email address - it
triggered the error message but there was nothing obviously wrong with
it. Very frustrating.