Endre, Exchange only sends one reply to each sender (https://learn.microsoft.com/en-us/troubleshoot/exchange/client-connectivity/one-reply-sent-sender), and it's also configurable too (https://learn.microsoft.com/en-us/troubleshoot/exchange/email-delivery/understand-troubleshoot-oof-replies).
Ryan Hamel ________________________________ From: Endre Szabo via NANOG <[email protected]> Sent: Monday, November 10, 2025 10:50 PM To: [email protected] <[email protected]> Cc: Endre Szabo <[email protected]> Subject: Re: [Ext] trolling Caution: This is an external email and may be malicious. Please take care when clicking links or opening attachments. On Mon, Nov 10, 2025 at 15:14:26+0000, Giorgio Bonfiglio via NANOG wrote: > Also, speaking about technical limitations - which mailserver in the world > does send one auto-reply PER MESSAGE to the same sender? I haven’t seen this > in ages, most seem to be sending only once or at worst once every day or so. Oh, I know the answer to this one! It's a niche player in the market, and it's well known for not following standards or best practices. Like, they could have ignored messages with List-* headers, for example, right? The server in question is called Microsoft Exchange. _______________________________________________ NANOG mailing list https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.nanog.org%2Farchives%2Flist%2Fnanog%40lists.nanog.org%2Fmessage%2FBUZSGS4UJJTCCBMVNGCFM7UDKQSDQTDA%2F&data=05%7C02%7Cryan%40rkhtech.org%7C264e6deb8b38433e14b908de20eea624%7C81c24bb4f9ec4739ba4d25c42594d996%7C0%7C0%7C638984406549222502%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=qLAd5BzYaaHxVcKz7oQhVd%2BzuDn49FbCu8Q4RRHhZrw%3D&reserved=0<https://lists.nanog.org/archives/list/[email protected]/message/BUZSGS4UJJTCCBMVNGCFM7UDKQSDQTDA/> _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/BRXFVZBOV3TQZAFCV2IVOXEIXEL4DMSC/
