I have just moved a customer’s Classic ASP website to their own VPS server (Windows 2003, 32-bit, IIS6, Virtual SMTP server) and after about 12 hours the website starting failing whenever it tried to send emails (CDO.Message).
Any script that sent an email took a very long time before it returned the error: Active Server Pages, ASP 0113, Script timed out. The standard timeout is in place. Strangely the custom error page which sends errors to me using the same email send method and settings (same function actually) was able to send me the error notification.
I needed to get the website going so I stopped/started the SMTP server which didn’t help, then restarted IIS which resolved the issue immediately.
I am worried this might happen again. Any suggestions for what can cause this problem or does the default SMTP server need some additional settings to cope with a reasonably high-volume website?
I later found that the actual sending of the email was not causing the problem but the fact that I was generating the HTML body for the email by retrieving HTML from another ASP page (via the XML object).
I tried various things to fix the problem including switching mail components (to Jmail) and using different versions of the XML object but the problem would still occur intermittently.
In the end I changed the code to generate the HTML for the email body instead of calling another ASP page and reading it’s response.
Eliminating use of the XML object seems to have resolved the problem but the cause was never found.