Having started this topic and searched around to find out what’s going on I have to say I’ve had virtually no help.
As I see it, the trouble is this is not a Spamhaus problem or a Gandi problem, or directly an ID or Three network one either, it’s an interaction between them which no-one wants to own.
I think the Spamhaus approach is a little out of date. What they’re doing is monitoring spam sent from various IP addresses and compiling blocklists which responsible providers like Gandi apply. In the past when everything used fixed IPs this would have been a good policy but now most things such as phones or mobile routers get assigned a dynamic IP when they connect. Some sort of irresponsible operator is sending or relaying spam using the block of IPs assigned to ID, maybe because it’s so cheap to connect. The IPs they’ve used get logged by Spamhaus and put on blocklists but what they’re doing is playing ‘whack-a-mole’ with the spammers. By the time the IP gets listed the spammer has moved on but the IP has gone on the blocklist for 12 months and if your router or phone is the next thing to pick that IP it’s you that gets blocked. As more and more IPs get blocked maybe eventually someone will do something about it. There seems to be something odd going on anyway as if you look at the alleged spam send in your problem 92.40.204.246.threembb.co.uk that appears to have come directly from the Three network mail server. According to their policy that should have been impossible - Hutchinson 3G actually say “You may not send emails directly from the Three network” from IPs in this range so I wonder how it even happened.
Anyway as I see it you’ve got at least three options:
- Operate through a VPN so you will present a different IP to the outside world. A friend of mine on ID has done this and it works.
- Register with SMTPGO https://www.smtp2go.com/ and send from their SMTP server instead of Gandi’s. You’ll have to add some lines to your Gandi DNS which you can get from SMTPGO’s Help. That’s free as long as you send less than 1000 emails a month.
- Dump ID and use a more expensive provider with proper help and a different IP range. I’m now using the EE network on a contract SIM with a Vodafone PAYG SIM as a backup with absolutely no problem so far.
Good Luck!