System.Net.Mail.SmtpException: Insufficient system storage. The server response was: 4.3.1 Insufficient system resources

Question

I\'ve recently designed a program in C# that will pull information from SQL databases, write an HTML page with the results, and auto-email it out. I\'ve got everything worki

Answer 1

To narrow down the issue definitively, you could swap in a different mail client like aspNetEmail (you can get an eval version to test), it wouldn't take but a few lines of code. If the problem persists, it is on the server; if not, it is on the client. I would strongly suspect this is a problem on the server, however, as when the client closes the connection and the message is sent, the server should really not be holding any resources as a result of that connection. You could verify this by looking at your SMTP logs and making sure there was no SMTP error when the connection was closed.

If this is indeed a problem on the server (the SMTP log shows clean disconnection and the problem is replicable with an alternate client), then I would log onto the server (if you can get access), and watch the disk space as jeuton suggests.

Answer 2

In exchange 2007 the c: (system drive) needs about 4GB of free disk space. This was our problem. Increment the drive and the mails will flow again.

Answer 3

This error can happen when:

1. The exchange server is out of disk space.
2. The recipient mailbox is out of disk space.

It is more common to run into issue #2 than issue #1.

Here is a list of Exchange Status Codes and their meanings.