We are having heavy troubles with our installation the discoverhotmail.com.It has tendency to send the end a big amount the emails, however when it concerns an email address which does no exist, it sort of hangs up and keeps circling through all wrong email addresses trying come send countless times.

You are watching: 550 invalid dns mx or a/aaaa resource record

In the log in it says “Could no instantiate letter function”, once running on php mailer, or “mailbox do not have invalid DNS MX or A/AAAA source record”, when running top top SMTP. For some reason this is not tackled by bounce management, however blocking the system. Now, that is sending with 1 letter every 80 seconds (and walk slower) instead of 3,500 every hour, which would certainly be normal.

I would be happy, if anyone could give me one idea, where this is comes from.

No one with an idea?


The ‘could no instantiate mail function’ method that discoverhotmail.com cannot attach to the mail server, and also the ‘invalid DNS…’ way that over there is no a letter server configured for the domain of the email recipient’s email address.

I’ve seen the an initial case once hosting companies disable the mail service on her vps.For the second error, girlfriend would want to blacklist that email deal with so that the server doesn’t store trying come send a article to them.

Hi Dan,

Thanks for your email!

I read around the an interpretation of “Could not instantiate mail function”, but this can not be the reason. Since the mechanism sends the end 10,000 email before beginning to do problems.

I deserve to blacklist this address, yet it’s part 350 email addresses, and I can not blacklist all of them. Ns thought, discoverhotmail.com would blacklist bounced emails automatically? and isn’t this sort of error sort of a bounce? i’m puzzled…

If you space using discoverhotmail.com in a VPS hosted by someone like GoDaddy, etc… climate they can turn off the mail duty because they see two numerous bounces, or you have exceeded your send limits etc.

I’ve viewed discoverhotmail.com get stuck on an e-mail that it can not send, my suggestion is come look at the device log, number out what the email attend to is the is leading to the problem, and blacklist that email address.

Hi Dan,

Today we sent out out one more newsletter through a tiny over 2,700 recipients. 56 of these were bounced through the message: “SMTP Error: The complying with recipients failed: (email address): Requested activity not taken: mailbox do not have invalid DNS MX or A/AAAA source record”. This keeps circling.I set up a bounce dominance with that (expression: “* invalid DNS MX *”, Action: “Add email resolve to the do-not-send-list and delete bounce”), however for some reason which i don’t understand, this ascendancy is constantly being ignored. Checking bounce rules says: “0 bounce suitable current energetic rules”

I don’t get it anymore…

You don’t should use the asterisks… adjust the ascendancy text to:

invalid DNS MX

these are continuous expressions, for this reason it will search the bounced email for the exact text you placed in there… in her case, it’s in search of the asterisks also.

Regular expressions are a little of one arcane science… powerful, deserve to do virtually anything, you must know specifically how they work. If you want to understand them, a couple of great programs room regex buddy, and textpipe pro.

For the functions of discoverhotmail.com and bounce rules, I simply put the message I want to enhance in the rule. The the easiest means to execute it.


Hi Dan,

Thank friend for your reply!Unfortunately this isn’t the solution, together I experiment with and without asterisks. Very first I had it without, then with.

I simply restarted the process, and it was finished through an error message, that the attachment was not discovered (although that is unchanged because Friday). The 56 bounced emails are still not marked as to be on the blacklist.

Do girlfriend know, just how discoverhotmail.com sends out email? let’s say, I have actually a stack 10,000 email addresses. 9,000 occupational as they should.

Then I have 300 wrong email addresses. Will discoverhotmail.com get stuck v this ridge (as that is bigger than the batch size) and also will constantly try to send the not correct emails, or does the skip this batch and move come the next (to return later)?


I’m not sure just how discoverhotmail.com exactly sends out emails. I have seen it go with a entirety list, and also get stuck on one or two at the end, when I looked at the resolve directly in the database, it had some invalid characters in it. The equipment for me to be to delete that address from the database and the list.

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Hi Dan,

That’s additionally my impression (on a enlarge level): It got stuck on some point to the end. When I turned off the corresponding addresses, the went through.