Solved

SMTPException: Failure sending mail

Posted on 2009-03-30
2
2,004 Views
Last Modified: 2013-12-17
Hi

In my asp.net 3.5 web application, I try to send email to multiple persons (almost 100) using for loop.
It works fine when email has no attachment. But, when email contains the large size attachment (300 KB), after sending 25 emails, it gives a smtpexception:"Failure sending mail".

I have tried using different size of attchment files and I noticed that its giving an exception when the email attachment size reached about 7 MB. (total size of the emails sent with attachment).

What should I do to resolve this problem?
0
Comment
Question by:aplusexpert
2 Comments
 
LVL 26

Expert Comment

by:jar3817
ID: 24097665
Maybe you're hitting some memory limit for your application. I'm a php guy, so I'm not terribly familiar with asp.net, but I know with php there is a default setting that limits the amount of memory for a script. Maybe you could up this limit to accommodate the size of the email (body + attachment) times the number of recipients.
0
 
LVL 7

Accepted Solution

by:
aplusexpert earned 0 total points
ID: 24877569
Hi

We found that this problem occurs due to the limit of the session size for SMTP server in IIS.  The default size for Limit session size to (KB): is 10240 (10 MB). It is the total size for sending emails for one mail session. So when our application sends email in a loop and the total email size exceeds this limit, it stops. So depending on mail size, you would be able to send x number of mails where x = Limit/Mail Size.
 
Suggested Action:

We can increase the session limit for the session to 50 MB or 100 MB.

This can be done as follows:

1. Start IIS (Internet Information Services).
2. Right click on Default SMTP Virtual Server and select Properties.
3. Select Message tab.
4. There is an option Limit session size to (KB). At present that value for this option has been set to 10240.
5. We can set this value to 51200 (50 MB) or 102400 (100 MB) or anything else as per our requirement.

Thanks.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

New-MailboxSearch Powershell Command and step by step approach to Search and Extract Emails form Exchange 2013 Journaling server.
Resolve DNS query failed errors for Exchange
Familiarize people with the process of utilizing SQL Server stored procedures from within Microsoft Access. Microsoft Access is a very powerful client/server development tool. One of the SQL Server objects that you can interact with from within Micr…
Nobody understands Phishing better than an anti-spam company. That’s why we are providing Phishing Awareness Training to our customers. According to a report by Verizon, only 3% of targeted users report malicious emails to management. With compan…

831 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question