I have an E-Mail requirement/problem that I've wasted several hours on over the past few days to little effect. Maybe someone here can help.
My home (linux) machine runs all the time and hosts the domain zbmc.eu which is registered at gandi.net. The zone file there is configured to point at my home machine and the MX record is set up too:- chris@cheddar$ host zbmc.eu zbmc.eu has address 84.92.49.234 zbmc.eu mail is handled by 10 zbmc.eu. chris@cheddar$ 84.92.49.234 is my PlusNet ADSL connection.
I have several domains hosted at TsoHost with associated E-Mail addresses (e.g. chris@isbd.co.uk, chris@isbd.net, cl@isbd.net). These all eventually forward their E-Mail from the TsoHost servers to chris@zbmc.eu. I run a postfix server on my home machine which receives these E-Mails and puts them in my mail spool. This has been working fine for several years.
However I now want to send E-Mail from the 'outside world' to chris@zbmc.eu. The specific requirement is to send errors from cron on various SBCs to me and I originally thought it was a misconfiguration at the sending end was the problem but it's more general.
No mail sent from outside to chris@zbmc.eu arrives on my home machine, it just disappears, no errors, no bounces, nothing.
Bit it works from the TsoHost cloud servers, why can they send E-Mail successfully to chris@zbmc.eu whereas no one else can?
I have done lots of tests and experiments so far:-
I've tried sending from three different sites (PlusNet, Gandi and a Linux box) to chris@zbmc.eu, mail just disappears. Identical E-Mail sent to chris@isbd.net arrives OK.
I have a postfix server set up on my Beaglebone black in France (to send the cron messages). If I monitor the mail.log file when connecting to the SMTP server at TsoHost (mail3.gridhost.co.uk) the logging is exactly the same for mails sent to chris@zbmc.eu as for mails sent to chris@isbd.net.
Wierdly (and this is what confused me somewhat at the start) I have an identical postfix setup on a Raspberry Pi on my home LAN, also for sending cron errors. It connects directly to the same SMTP server at TsoHost as the Beaglebone does. However E-Mail to chris@zbmc.eu from the Pi works!
So it would seem that there's something 'out there' that's routing mail for zbmc.eu to the wrong place (or nowhere), but it doesn't get at the mail sent from within TsoHost for some reason. I.e. TsoHost seems to do what I hoped/expected with E-Mail for chris@zbmc.eu but no one else does.
Help! :-)