Spam Resources
Mail Blocked by Osirusoft Relays List
Your E-mail to our mail server was rejected because your mail server (), is listed by the Osirusoft Open Relays list. If you do not understand what an Open Relay is, see our Open Relay FAQ. You need to contact the technical staff who operate your mail server and send...
How SMTP and Internet Email Systems Work
Internet E-mail is transferred between systems using a protocol known as SMTP, or the Simple Mail Transfer Protocol. The basic functionality of SMTP is described in RFC 821. Additional functionality has been added over the years, but in essence, RFC 821 describes what...
Is Your Mail Server Blacklisted?
Many mail servers block email from IP addresses used by mail servers accused of sending spam. If your mail server's IP address is "blacklisted", mail sent by your server will bounce back or simply disappear. If you suspect your IP as been blacklisted,...
The Structure of an Email Message
As you learned in How Internet E-mail Systems Send E-mail, Internet E-mail servers don't really care what is in an E-mail message. However, the software people use to create and read messages certainly does. RFC 822 describes the correct format of the structure of an...