HikaShop using "phantom email address"

-- url of the page with the problem -- : local dev server
-- HikaShop version -- : 2.3.0
-- Joomla version -- : 3.3
-- PHP version -- : 5.3.27 (MAMP)

Gentlemen,

I fear I need to post again, sorry sorry. But you find me baffled by the fact that HikaShop is sending out emails using an email address that's nowhere in the entire system.

So, here the facts:

Say my domain in Joomla/HikaShop is my_domain.com. Promptly, and especially during development, I've set all (all!) email addresses - in Joomla's global config, in HikaShop, even in other extensions incl HikaMarket - and all sending and reply-to addresses to info@my_domain.com.

I just double-checked all email fields, particularly in HikaShop's config and as far as I could think systemwide. I even searched the database for what HikaShop is using (thankfully not too many...), the phantom mail address which HikaShop uses as "Return-Path" address according to the mail header is nowhere in the system. Nowhere.

I only stumbled over it when a mail bounced, and it bounced to TM@my_domain.com. "TM" in uppercase, and only that. Neither is this address anywhere in humanly readable text in the system, not even "TM" alone (yup, searched the database for it), nor have I in my long life spelled the part before the @ in an email address in uppercase. Ever.

Now, here you go... two more funny - or strange? - facts:

1. "TM" are my initials, and the email address tm@.......... does exist. After all, this way I got the bouncer. Except, I never ever used it in uppercase. Please note, as stated above, this address is not anywhere, also not under "Bounce Address". Actually, the field "Bounce Address" is empty. Not entirely sure, but I believe it's empty since day #1
2. Few moons ago, I had tm@my_domain.com for a brief period as "Send email for new comments" under "Vote & Comment" - briefly only, and before I decided to not use Votes & Comments at all. Since then also "info@my_domain.com" decorates this otherwise useless field. Anyway, did "tm" stick and transform to an evil "TM" over time??

Help. Please help. I can deal with a lot, but I'm not ready for fighting phantoms or ghosts...

Thank you. Needless to say, if I screwed somewhere somehow, tell me. I'd be very surprised, but it better hurts then. Baaad.

Big thanks again for your response, Nicolas.

Oh well.

My HikaShop setup is clean, as mentioned. And the emails themselves couldn't be an option as I hadn't even gotten to editing any, yet.

Then your golden hint with the mail server. Gosh. I'm running under MAMP and am using PHP Mail due to another extension requiring it. Quick look, and - dang!
Some 137 years ago I've set up the server to run as user... - correct, my initials in uppercase. I myself am the phantom, it's been nothing but a Jekyll & Hyde scenario.

Much time wasted with digging (my bad - I seriously apologise for wasting yours!), thanks for teaching me, lesson learned.

Now, while I go and dig a hole for myself to hide in, can someone please delete this thread?

P.S.: Yes, it hurts.

Haha, needless to ask, it's your forum = your decision, and of course I don't mind.

I'll just dig my hole a bit deeper then...