Ten threads is about optimal for sending email - as you add more threads, your destination server may become overloaded or your internet connection may reach saturation. Should messages fail to be conveyed to your mailserver, Mailer will automatically attempt to resend the ones that failed for you.
A Few Kudos...
5 Cows at TuCows!
Dr. FileFinder Likes Mailer!
Easy to Use Automatic Emailer
Send email messages automatically to an unlimited number of customers,
at speeds of over 10,000 messages per hour! Simple, Fast, and Effective. Free License available.
Fast Sending. Easy Scheduling. Mach5 Mailer has the power to get the message out using a remote SMTP Server, Local SMTP or Mailer Express! Full ESMTP, SSL, and TLS authentication support.
Fast, Multi-Threaded Sending
Mailer can generate up to 30 messages per second and is designed to take advantage of modern Multi-core CPU's.
Mail Scheduling Built-In
Schedule multiple mailings to fire off as often as you like.
Actively Supported, Developed, and Updated
Mach5 Mailer is constantly updated and upgraded with new features, many taken from customer suggestions. We recently released Mailer 4.5 with full Windows Vista support, a free upgrade for all our Mailer 4 customers.