Recently I installed iRedmail at work so that we could include DKIM signatures in our newsletters. Every week we send out a newsletter to 96,000 former customers. It takes about 13 hours to send the newsletter. Yahoo is probably our most important email domain and they want us to implement DKIM. A couple of weeks ago we started seeing Yahoo limit our sending rate. Obviously they had a problem with something in our newsletter. So we re-analyzed the error codes we were getting during the newsletter mailing and implemented DKIM. The problem is fixed. Here is how I implemented this version of iRedMail.
I implemented a VMware version of iRedMail to sign newsletter emails using DKIM. I used Ubuntu 9 server version(optimized for VMware version) to build appliance.
- The server works as a mail proxy in front of the SMTP server we use exclusively for the newsletter. It signs and relays the email to the existing SMTP server. I kept the existing SMTP server so that I could continue to use my existing procedures for parsing the log files to identify old/obsolete mailboxes.
- I created iRedMail users in LDAP to relay local users to mailboxes on Exchange.
- My primary bottleneck is still my mail transmission to the Internet speed, 2 per second. I can create newsletter emails at about 8 per second.
- On an old Proliant DL350 G4 iRedMail consumes about 40% of the dual CPU computer for four hours.
Since I had experience installing iRedMail it went quickly. The biggest bug I had to fix was the AWStats/permissions problem on the mail.log file.