What is the size limit for email messages and attachments? August 25, 2016August 29, 2016 by nickpetros nickpetros No comments yet The maximum message size allowed for a single email message is currently 500 megabytes. Post navigation Is it safe to turn off the anti-virus program on my computer?Will pointing my MX record to SpamRaptor affect the deliverability of my outbound messages? Comment on this FAQ Cancel replyYou must be logged in to post a comment.