SMTP stuck in queue - BDAT LAST

On an *occasional* pc on our network, mails can't be sent through smtp because they get stuck in the queue because the local SMTP service is sending a BDAT LAST command before it has actually sent any of the message body. We have narrowed down the problem to this. 90% of the pc/servers on our lan can send the smtp messages no problem, but an occasional one exhibits this problem, even after restarting smtp/iis/os. The 90% that work and the 10% that don't all have the same smtp configuration. Come to think of it, the problem seems to usually happen on windows2000, but by the same token, many other win2k pc/servers work fine with the smtp.

is there a fix or workaround for this?

i have already read:

. . .but there wasn't much really useful info there. and i don't go through hotmail so i'm not sure it pertains to me.
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hello,  first some semantics:

>> mails can't be sent through smtp

it's worth clarifying that mail is not technically "sent through" the smtp service.  firstthe client delivers the mail to the smtp server.  if the server accepts it, then the client disconnects with success.  if not, the client (eg outlook) will proviode some sort of feedback to the user that the delivery failed.

now, the server either has the message or not.  if it has the message, then the server initiates a further delivery process (exactly the same as the process used by the client to deliver to the server) to forward (or relay) the email to the destination server.

once again, the destination server either accepts or rejects that email.  if it is accepted, then it is considered as delivered.  if not, then depending on the failure cause stated by the remote server, the local smtp service will either bounce it (send a NDR back to the originating client) or will add it to the queue and try again later.

so let's clarify:

is it the client displaying a problem, or the server?

SweatCoderAuthor Commented:
>> "the local SMTP service is sending a BDAT LAST command before it has actually sent any of the message body"

problem is on the client. the server is fine because 90% of clients deliver successfully to the same mail server.
OK, this is what is confusing me then:

>> mails can't be sent through smtp because they get stuck in the queue

what queue?

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SweatCoderAuthor Commented:
i'm taking it you don't have much experience with smtp. . .  :-)


this is a folder dedicated to smtp on every windows os. the phrase "stuck in the queue" always refers to this folder. when delivery is unsuccessful, 99% of the time it will either go into this queue folder, or into the "badmail" folder at the same level.
>> i'm taking it you don't have much experience with smtp. . .  :-)

in fact i'm talking from about 6 years experience with iis and smtp server.

>> problem is on the client.
>> mails can't be sent through smtp because they get stuck in the queue

you must see that these are mutually exlusive statements.  if the problem is at the client, then the message could not possibly have made it to the queue.

so now we get to the point that I am able to advise with a fair degree of certainty that the problem is NOT at the client, but at the server.

OK, so you suspect that the client is *causing* the problem because it happens only with some particular clients and not with others.  well that may be the case, but the fact remains that the mail is accepted and queued by the smtp service, and therefore, by definition, the problem is at the server.

If you want to find a solution, then look in the place where the problem is happening.  Check the smtp service logs to find out what error is causing the mail to be queued.

Incidentally, if there is some kind of antivirus system in place somewhere, i suggest that you disable it for the time being while testing.  some mail scanning services are broken and do not properly handle BDAT in particular.


suggest accept meverest.
SweatCoderAuthor Commented:
it's not abaondoned. i put a post in the Administrative area to have it closed some time ago. No useful answers were given, just some generalized thoughts. No offense intended.

To award points would suggest that a solution was offered that solved the problem. No such solution was given.

>> it's not abaondoned.

There is no comment after my most recent one, which contains what I beleive are valiud comments, whether or not you choose to agree with them.  You have made no further attempt to discuss the comments or attemtp to work toward a solution.  Essentially, my last comment has been ignored, and therefore, the question is abandoned.

suggest paq.

Please note that these comments are ventured as an opinion and not as personal criticism.  You should review the contents of the link you provided.  In it, the Moderators instructed you to respond to meverest's post.  Your request to close the question was rejected on the grounds that you failed to do so - for an idea why, see

Though I wouldn't presume to speak for them, I get the impression that the Mods agree that it appears that the recommendations made by meverest were on the right track.  If no solution has been provided yet, the primary cause is the fact that the question has been abandoned by the asker.  Under E-E guidelines, you have some obligation to respond to comments such as these rather than abandon the question, which you did (as defined by E-E).  If that doesn't impress you, I would point out that you have answered a few questions yourself, so you understand that the experts on E-E are professionals offering their valuable knowledge and experience free of charge.  That fact alone implies an obligation to work with those who try to help us when we ask questions ourselves.

PAQed with no points refunded (of 500)

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