How to avoid 550 errors when switching hosting providers
I’m in the process of moving my sites and my clients’ sites over to my MediaTemple (gs) account at the moment, and had been getting frustrated at repeated errors when trying to send email. I finally figured out last night what the problem was.
550 user not found
When trying to send email to my clients or to one of my other addresses, Outlook was refusing to send anything and returned a ‘550 user not found’ error every time, no matter what I tried.
Eventually it dawned on me; I had created domain aliases for all my client sites on the server prior to transferring them across, so when I sent an email to bill@myclientsite.com, the SMTP server was helpfully checking my server first, finding the domain (even though it was not registered or even pointed at that server), seeing there was no matching email address, and bouncing the email back to me.
You would expect it to look up the MX records in the DNS first, but because I’d already setup the domains on the same box it never reached that step, causing my problems.
So, the moral is – don’t create domain aliases on your server until you’re actually ready to move the domain onto that server, as you may accidentally prevent yourself from emailing any of your clients!
Filed under: Technology, Internet.
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