Piecing together the building blocks described in previous section is the last
crucial step in setting up your MTA. Nearly everything in slimta starts with
Edge service which receives messages. They hand messages off to a
service which talks to a
QueueStorage object to persistently store messages.
The queue initiates delivery attempts with a
Types of MTA Servers¶
If you read the Terminology page, there are MTAs, MDAs, MSAs, as well as other special configurations like Smart hosts, SMTP proxies, or Mail hubs. Depending on how you sub-class the different building blocks of a slimta MTA, you can pretty much handle any of these configurations.
MSA: An MSA is all about taking a message from a mail client like Thunderbird and delivering it to its next hop on the Internet. Check out the Mail Submission Agent page.
Smart Host: A smart host takes messages and delivers them to a specific destination, rather then dynamically looking up the recipient’s destination. Use a
SMTP proxy: An SMTP proxy skips the
Edgeand directly attempting delivery with a
Relayand returning the success or failure back to the edge client. SMTP proxies are not yet supported by slimta, but they are on the radar.
Mail Hubs: A mail hub is a pretty generic term, but one particular use could be a dedicated spam scanner. It receives messages by any
Edge, calls the
SpamAssassinpolicy, and delivers the result to another MTA with a
StaticSmtpRelayfor further processing.