Is anybody familiar with nullmailer? I had a phonecall from Plusnet this morning telling me that something on my network was attempting repeat connections to their SMTP server with incorrect credentials. Odd, I thought, and checked through my phones (my desktop and laptop were off). In the end it turned out to be nullmailer on my Linux box. Nullmailer was originally configured to email me CCTV footage at work from Zoneminder, but after getting fed up with false positives I turned this off from within Zoneminder and forgot all about it (until today). A few weeks back I changed my Plusnet password, and obviously forgot to change the password in nullmailer (in all its plain-text glory). Looking back through my logs, nullmailer appears to flip between insane and ridiculously insane, when confronted with a login rejection. Sometimes it would re-attempt every second (this in itself is ridiculous) but at times was attempting over 150 attempts per second. Then back to every second. Both scenarios are ridiculous. I've removed it completely for now, but is there any way to make it behave itself?