[buzer]

> The Reddit thread suggests the recipients’ emails are likely ARIN IP range contacts.

It's likely multiple different sources. I just noticed I got it as well on my personal email (which has custom domain) and I don't own any IP ranges.

[_jal]

Yeah, I got it to two accounts I use with ARIN, as well as another that is confusing me.

That one is not very old, I know I have the entire outbound history for it, and have not used it for ARIN or anything similar.