Forum Moderators: phranque
We have around 200,000 registered users (and counting), half of them have agreed to receive monthly newsletter. We have two dedicated servers (one for IIS and other for SQL Server). Mails are sent using IIS 6.0 Virtual SMTP server.
Mails sent are always personalized, hence are fetched directly from database. What we do right now is, send 500 mails then wait for one minute. Send 500 mails again. When we start sending mails, the speed is around 50 mails per second which keeps on dropping as the process proceeds. As the speed slows down, mails start accumulating in queue. As the number of mails in queue reaches 3000, the speed drops to 1 mail per second or even lesser. The next step is to stop generating new mails and restart virtual SMTP mail server. After restart, things start working again. The process continues and it takes up to seven days to send 100,000 mails.
Since the number of mails to be sent every month is increasing, we are worried about the issue. Windows SMTP server seems to be the culprit. Our research says we have three options.
1. Use third-party newsletter sending bodies. But we have an apprehension that they might use our user database. User privacy is the top priority and we just don't want to compromise on it.
2. Use third-party SMTP server which is capable of sending 100,000 emails in a day or so. But we don't know which one is the best.
3. Use some bulk email sending software. But not sure which one to go for.
Any inputs in this would be of great help.
[edited by: engine at 9:32 am (utc) on Nov. 16, 2007]
[edit reason] No urls, thanks. See TOS [webmasterworld.com] [/edit]
You are right, file access would be slower if files in a folder are too many. But I am not talking some hundred-thousand files. Mail delivery starts getting slow after sending 1,000 mails, no matter how many files are there in the folder. In maximum cases, files in the folder are not more than 2,000. Do you still think this number is too huge for Windows File System to handle? Or the problem lies somewhere else?