I sent an e-mail query on July of 2008, and heard nothing. I went over my list this past February, and sent followup e-mails to a number of "hanging" queries where I had heard nothing for six months or more.
The Irene Goodman agency was one of these. Shortly afterwards, I got this in e-mail:
I did resubmit, and was rejected about a week later, but it shows it never hurts to follow up if you think way too much time has passed.
The Irene Goodman agency was one of these. Shortly afterwards, I got this in e-mail:
"If you haven't received a response, it's likely that it was lost in transit. We sincerely apologize - please resubmit it and I'll make sure Ms. Kriss gets it."
I did resubmit, and was rejected about a week later, but it shows it never hurts to follow up if you think way too much time has passed.