Maintenance for the week of April 7:
• [EXTENDED] ESO Store for maintenance – April 09, 2:00PM EDT (18:00 UTC) - 11:00PM EDT (03:00 UTC)
• ESO Store for maintenance – April 10, 12:00PM EDT (16:00 UTC) - 3:00PM EDT (19:00 UTC)
It's because mass messages can be seen as spam by the system. I don't know if anyone actually was permanently banned, but people were auto-suspended/kicked for spamming in the past. These trigger cases are reviewed, though. I don't think it's anything to worry about, even if something does happen, it should be easy enough to submit an appeal. Lots of guilds use these mail addons.