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Getting error 452 4.5.3 Too many recipients

On Microsoft » Microsoft Exchange server

8,035 words with 2 Comments; publish: Fri, 23 May 2008 10:09:00 GMT; (300155.27, « »)

I have some clients who are using Outlook 2003 to send email to a list

of people.

The account they are using is an IMAP account on a exchange 2003

server.

The list varies in size from 5 to 500 recipients.

The problem is that sometimes (sometimes) the message will bounce back

with an error like the following

________________________________________

_________________

Your message did not reach some or all of the intended recipients.

Subject: REMINDER: Final Exam on Wednesday!

Sent: 12/13/2005 9:58 AM

The following recipient(s) could not be reached:

'xxxx.ms-exchange.questionfor.info.xxx.xxx' on 12/13/2005 9:58 AM

452 4.5.3 Too many recipients

'xxx.ms-exchange.questionfor.info.xxx.xxx' on 12/13/2005 9:58 AM

452 4.5.3 Too many recipients

________________________________________

__________________

1) this error is NOT consistent for every message sent out to a large

number of recipients.

For example:

Client will send an email with 300 recipients and the mail will go

just fine

Client will later send an email with 50 recipients and the mail will

bounce back with the above error.( yes 300 got sent successfully then

later in a separate email ,50 bounced back)

2) The SMTP settings on the exchange server for max recipients is MORE

than the max number of recipients the client has ever tried to send to.

I've seen the setting and set it myself.

3) this error sometimes shows up when the total recipients are less

than 5!

The inconsistency of the error and the fact that the server setting for

max recipients is well above what the client is sending leads me to

think this is a bug with either outlook or exchange.

I have googled this error and found that most people assume this is

caused by a server setting. I agree that this message CAN be caused by

the SMTP max recipient setting, but in this case it is not.

Some people say this is a caused by the junk-mail filter in Outlook and

that a patch will fix it. I know for a fact that the client's

machines are fully patched and they still get this error.

Does anyone actually know how to fix THIS problem/BUG?

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  • 2 Comments
    • kazumi.amano.ms-exchange.questionfor.info.cba.ufl.edu wrote:

      >I have some clients who are using Outlook 2003 to send email to a list

      >of people.

      >The account they are using is an IMAP account on a exchange 2003

      >server.

      >The list varies in size from 5 to 500 recipients.

      >The problem is that sometimes (sometimes) the message will bounce back

      >with an error like the following

      > ________________________________________

      _________________

      >Your message did not reach some or all of the intended recipients.

      > Subject: REMINDER: Final Exam on Wednesday!

      > Sent: 12/13/2005 9:58 AM

      >The following recipient(s) could not be reached:

      > 'xxxx.ms-exchange.questionfor.info.xxx.xxx' on 12/13/2005 9:58 AM

      > 452 4.5.3 Too many recipients

      > 'xxx.ms-exchange.questionfor.info.xxx.xxx' on 12/13/2005 9:58 AM

      > 452 4.5.3 Too many recipients

      > ________________________________________

      __________________

      >

      >1) this error is NOT consistent for every message sent out to a large

      >number of recipients.

      The number of recipients isn't the number of addresses in the "To:",

      "Cc:", and "Bcc:" headers, it's the number of RCPT TO commands sent in

      one SMTP transaction. And the 4.5.3 status isn't sent by your server,

      it's just reported by your server. The culpreit is the target domain's

      server. You have no control over this. Some ISP's set the number of

      allowable RCPT TO commands to a ridiculously low value (I've seen it

      set as low as 1).

      > For example:

      >Client will send an email with 300 recipients and the mail will go

      >just fine

      >Client will later send an email with 50 recipients and the mail will

      >bounce back with the above error.( yes 300 got sent successfully then

      >later in a separate email ,50 bounced back)

      I'll bet that the 300 weren't all sent to one domain.

      >2) The SMTP settings on the exchange server for max recipients is MORE

      >than the max number of recipients the client has ever tried to send to.

      >I've seen the setting and set it myself.

      Which "max recipients" are you referring to? The one in the "Message

      Delivery" property isn't the one you want to change. Change the "Limit

      number of recipients per message to:" value on the SMTP Virtual Server

      (if you're not running W2K3 SP1, contact MS PSS and get the hotfix

      that corrects the problem where this limit is mistakenly applied to

      inbound messages within your own organization!).

      If you set the value to, say, 100 and then send a message to 250

      recipients in the same domain, the SMTP server will send three

      transactions. The first two will send the message to 100 recipients

      each, the third will send to the remaining 50. The message originator

      still puts 250 recipients into the message. They never know (or care)

      that not all of them are delivered in one shot.

      Set the value to something that works for you -- or for the receiving

      domains. You can set it as low as 1, but that means that for every

      recipient you'll send the entire message. That can have a devestating

      effect on your bandwidth consumption. Setting it to 100 (the

      recommended "minimum maximum value in the RFC's) will cure this

      problem for the majority of your problems.

      [ snip ]

      >I have googled this error and found that most people assume this is

      >caused by a server setting.

      It is -- but not by YOUR server's settings.

      >I agree that this message CAN be caused by

      >the SMTP max recipient setting, but in this case it is not.

      >Some people say this is a caused by the junk-mail filter in Outlook and

      >that a patch will fix it. I know for a fact that the client's

      >machines are fully patched and they still get this error.

      >Does anyone actually know how to fix THIS problem/BUG?

      The "bug" usually lies with the sending server allowing more than 100

      recipients per transaction, OR by the receiving server allowing

      *fewer* than 100 recipients per transaction.

      Rich Matheisen

      MCSE+I, Exchange MVP

      MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm

      Don't send mail to this address mailto:h.pott.ms-exchange.questionfor.info.getronics.com

      Or to these, either: mailto:h.pott.ms-exchange.questionfor.info.pinkroccade.com mailto:melvin.mcphucknuck

      le.ms-exchange.questionfor.info.getronics.com mailto:melvin.mcphucknuckle.ms-exchange.questionfor.info.pinkroccade.com

      #1; Fri, 23 May 2008 10:10:00 GMT
    • Thank you!

      "The number of recipients isn't the number of addresses in the "To:",

      "Cc:", and "Bcc:" headers, it's the number of RCPT TO commands sent in

      one SMTP transaction. "

      I had to think about that for a min. And then it all, ALL began to make

      sense!

      The number of recipients refferd to in the error message is not the

      number of email addresses in the addressing fields.

      We have been chasing down and troubleshooting the wrong "recipients".

      You are right. all the messages were not sent to the same domain, only

      the messages that bounced were sent to the same domain.

      The "Limit number of recipients per message to:" value was the one

      that we had changed. it was some astronomical number like 60,000. we

      had changed it down to 5000 thinking that would help prevent problems.

      obviously we didnt make it low enough.

      Thanks for clearing that recipient term up and explaing the

      relationship between connections and recipients! Makes all the

      differnce.

      #2; Fri, 23 May 2008 10:11:00 GMT