Our smartermail is version 14.2. Fews days ago during the weekend, our server suddenly is sending massive amount of spam. The spam is showing being masked as random username with correct domain names being hosted in smartermail.
For eg, we have domain1.com, domain2.com, domain3.com and so on. Spammer is using firstname.lastname@example.org, email@example.com, firstname.lastname@example.org and so on.
Even the IP is connecting from all around the world. Like brazil, europe, asia and so on.
We search and search but was unable to find where is the spam coming from or how the spammer is doing it. So bad that our IP got blacklisted and we get complains from ISP.
We have posted a support ticket to smartermail but still waiting for their reply. In the meantime, would really appreciate if someone can shed some light into resolving this issue. This is really crazy and we have never seen this kind of high level spamming before.