Answer
STAFF
Sam Wierema
24-Mar-2011 05:52:39
As far as I'm aware there is no limit on Twittermail, except for the Twitter limit on of how many tweets you can send per hour.
Email not posting to Twitter can be caused by many things: email not arriving, email can't be read, Twitter API limit and some other causes. Unfortunately we currently don't have the infrastructure to debug the cause of the issue, so I couldn't tell you where the error is occurring specifically.