Mine was suspended for spam and I was falsely accused by Mailgun of have compromised servers. Initially I freaked out and then discovered that my servers were fine, but my account at Mailgun was hacked and used to send thousands of spam emails. This happened a couple of times. I asked to see the IP addresses of the senders and Mailgun said they didn't track that/could not tell me. And then they had the audacity to bill me for sending spam that was sent as result of their system being compromised.