|Subject:||Re: Strange SMTP Server Behaviour|
|Posted by:||Ciaran Costelloe (ccostell…@flogas.ie)|
|Date:||Wed, 26 May 2004|
Make sure DNS is set up correctly on both machines, it can give long
timeouts. To see exactly what is happening, get ethereal (free) which shows
all packets going in & out, and it will display them in real-time also.
"Pierre Roux" <pier…@infofx.co.za> wrote in message
> I'm writing a mail server using the TIdPOP3Server and TIdSMTPServer
> When sending a small message, everything is fine, however when sending
> larger messages (approx 1MB or bigger) things starts to go funny. Outlook
> just sits there for about a minute, and then the message goes through,
> unless a Gracefull disconnect occurs. All the events are triggered, and
> according to my log mere (milli)seconds apart, but it takes ages for the
> message to leave Outlook.
> Downloading the same message via POP3 takes milliseconds.
> - I've included Sleep(X) statements throughout, thinking it's the old
> Outlook issue.
> - When I step through the code and the whole SMTP process has finished
> except for the disconnection of the socket, the message still shows in my
> 'Outbox'. The disconnect is triggered long before the message disappears
> from my Outbox (after about a minute or so, message size depending). At
> this stage, I sometimes get a Gracefull Disconnect, and the OnDisconnect
> does not trigger - which should allways trigger if I understand Remy
> correctly. This is extremely hard to replicate, as you have to send a
> message and wait, and it might not occur. However, if it does occur, the
> error happens long after the last event in the proccess, and the only
> not showing up in the Event Log is the disconnection.
> Does Indy maintain the state of the TIdSMTPServerThread.SMTPState value?
> - I'm not touching it, as everything works the way it should on smaller
> I have no idea where to look anymore - any ideas?
> What event's code would you like to see?
> I've spent until early this morning on this, and nothing I tried worked
> I'm thinking it might be something environmental/external that plays a
> Small messages, say 2K or so, takes less than 1 second to process.
> I've tried eliminating as many possible environmental problems as
> - I have Norton Anti-Virus 2003 on my machine, but E-Mail scanning is
> disabled totally, as I was thinking it may play a role in the problem.
> - Running Indy 9.0.14, Development Snapshot, Delphi 7 on XP Pro
> - Checked directory search paths as I had Indy 10 on my machine and had
> issue with compiling with some of the wrong files before, but that's all
> fine and fixed now.
> - Everything runs on the same PC - IP Address & Port is 127.0.0.1:25
> At the stage when '[2004/05/26 12:53:26 AM] Message Accepted to User
> Account' is logged into the log file, the message is still in my Outbox,
> well as where it should be in my mail server.
> Log for 7MB file
> - actually only disappeared from mailbox after about three minutes
> - Same message took about three/four seconds to download
> - Looking at the log from start to finish is 13 seconds, yet it was still
> stuck in the outbox long after that!
> [2004/05/26 12:49:37 AM] SMTP Incoming Connection from ireland:3789
> [2004/05/26 12:49:38 AM] SMTP MAIL FROM …@x.co.za
> [2004/05/26 12:49:38 AM] SMTP RCPT TO …@x.co.za
> [2004/05/26 12:49:47 AM] SMTP Message Accepted to User Account
> [2004/05/26 12:49:50 AM] SMTP Disconnected
> [2004/05/26 12:49:50 AM] SMTP Closing Object
> With Gracefull Disconnect:
> [2004/05/26 12:39:37 AM] SMTP Incoming Connection from ireland:3792
> [2004/05/26 12:39:38 AM] SMTP MAIL FROM …@x.co.za
> [2004/05/26 12:39:38 AM] SMTP RCPT TO …@x.co.za
> [2004/05/26 12:39:47 AM] SMTP Message Accepted to User Account
> [2004/05/26 12:41:23 AM] SMTP Error: Connection Closed Gracefully.
Strange SMTP Server Behaviour posted by Pierre Roux on Wed, 26 May 2004