Re: Solving a "The server responded: #4.5.3 Too many recipients.." error

[John McGaw]

On 9/30/2015 12:27 PM, Thee Chicago Wolf [MVP] wrote:
> Trying to help out someone who just started to experience this issue
> the past few days.
>
> Whenever the user tries to send to more than one recipient, it throws
> a "The size of the message you are trying to send exceeds a temporary
> size limit of the server. The message was not sent; try to reduce the
> message size or wait some time and try again. The server responded:
> #4.5.3 Too many recipients.." error. This happened on 38.2.0. Upgraded
> the user to 38.3.0 with the same result. This is whether the message
> is small or big. Sending to *one* recipient works just fine. Google
> wasn't of much help.
>
> - Thee Chicago Wolf [MVP]
>

At first glance, it would appear that the server is a more likely culprit
than two different different versions of TB, especially since it cropped up
suddenly using the original version. Occam's razor and all that...

I'd be talking to the server's tech support people.

[David E. Ross]

To block spam, some servers block messages with more than one recipient.
Yes, this is over-kill; and a strong complaint should be lodged with
the ISP.

--
David E. Ross

The Crimea is Putin's Sudetenland.
The Ukraine will be Putin's Czechoslovakia.
See <http://www.rossde.com/editorials/edtl_PutinUkraine.html>.

[Linux User]

On 30/09/15 18:50, Chris Isle wrote:

> On Wed, 30 Sep 2015 11:27:05 -0500, "Thee Chicago Wolf [MVP]" <"."@.> wrote:
>
>> Trying to help out someone who just started to experience this issue
>> the past few days.
>>
>> Whenever the user tries to send to more than one recipient, it throws
>> a "The size of the message you are trying to send exceeds a temporary
>> size limit of the server. The message was not sent; try to reduce the
>> message size or wait some time and try again. The server responded:
>> #4.5.3 Too many recipients.." error. This happened on 38.2.0. Upgraded
>> the user to 38.3.0 with the same result. This is whether the message
>> is small or big. Sending to *one* recipient works just fine. Google
>> wasn't of much help.
>>
>> - Thee Chicago Wolf [MVP]
>

> Do they experience any problems when they attempt to send via the web interface of their mail server?
>

Alternatively, do they experience the same problems when they use
another ISP. For example, if Hotmail is giving this problem (in TB)
then try GMAIL (in TB) and see if the problem is still there.

[NFN Smith]

Thee Chicago Wolf [MVP] wrote:

>>> >>Do they experience any problems when they attempt to send via the web interface of their mail server?
>>> >>
>> >
>> >Alternatively, do they experience the same problems when they use
>> >another ISP. For example, if Hotmail is giving this problem (in TB)
>> >then try GMAIL (in TB) and see if the problem is still there.

> This is a corporate user and I have had trouble with their ISP's
> SMTP/POP/IMAP stuff before. They are pretty bad so I won't be
> surprised if the ISP did something on their end. I'll know more on
> Wednesday


If the user is seeing a 4.5.3 error, that's an SMTP error that's being
generated by the server, meaning that the server is refusing submission
of the message.

I can't tell if that's something that's deliberate as a policy thing, or
bad admin technique, but I'm inclined to believe a combination of both.

A 4.x error means "temporary error, please try again later", and means
that there's some sort of problem that should clear itself, in time.
When that happens in exchanges between servers, it means that the
sending server is being instructed to hold onto the message, and leave
it in outbound queues for later re-try of delivery.

To me, it's sloppy admin to return a 4.x error, if the problem is a
distribution list that's too long. There's likely no way that message
will *ever* be accepted, without the user cancelling the send attempt,
and then re-forming the message with an acceptable recipient account.
Thus, the error being returned should be a 5.x error (i.e. "permanent
error, don't try resending).

If it's a corporate server, it's a good guess that rejection of a large
distrib list is a policy thing, designed to inhibit the too-common
practice of "send copies to everybody that might remotely be
interested", and then where recipients send a follow-up blast to the
entire list with top-quoted "me too" responses.

Depending on implementation of the server, it may be counting the
addresses in To: and Cc: lines, but I wouldn't be surprised if it's
counting the number of addresses in the SMTP envelope (which is never
seen by users), and as a result, counting all the addresses (including
Bcc:), not just the To: and Cc: addresses that are visible.

This is definitely not a Thunderbird issue, and if you were to configure
any other SMTP client (Outlook, Windows Mail, Pegasus, The Bat!,
Sylpheed, etc.), the user would get exactly the same response.

Smith