SUMMARY

The maximum number of recipients that can be specified for a single message is 300. Users receive the error "452 Too many recipients" when they attempt to go over this limit.

DETAIL

By default the MailEnable server imposes a limit of up to 300 recipients to a single message. This is to help reduce the amount of spam sent if anyone does guess a users password. This value can be altered in the administration program under the SMTP Security options.

MORE INFORMATION

How to reduce the number of concurrent messages sent to remote mail servers?: http://www.mailenable.com/kb/content/article.asp?ID=ME020236