Need advice for mass mailer in Delphi

Question

I'm trying to develop a mass mailing application and would like to use Delphi for it. What components or libraries would be my best options (for Delphi7). Can they handle sending about 25,000 emails? The application is not for spamming, so I'm curious if correctly authenticating and playing by the rules will add some delay to the process?

Answer 1

I'd use the Indy components, which are in the box. Newer versions will let you also send to gmail and other servers under SSL.

They can handle even complex situations, they limitations are likely in the SMTP server you'll use for sending. They generally have significant restrictions, but they tend to be all different.

Answer 2

The problem with mass mailing is not so much your program, but it is the limits that your ISP will allow.

Many ISPs severely restrict you and will not allow more than a set quota per hour, day or month that is usually quite low, e.g. 200 emails per day. Penalties are severe, and they can suspend your account without giving you a warning first.

If you (or the people using your program) want to send out 25,000 emails or so within a reasonable time, say a few hours, you will need either a dedicated email server, or need to use the services of a high volume SMTP service.

Also make sure you research into Throttling and Batching your emails.