Diff b/w MX & SMTP servers ?

Question

what is the difference between an mx server and smtp server ? since both are used to deliver email to pop, correct me pls if im wrong ! Also pls anyone could explain how the email travels along the set of servers in both incoming and outgoing directions in similar and different email domains....

A detailed reply shall be highly appreciated...

Regards

Emad

Answer 1

There's no such thing as an "MX server". It's an "MX Record", a.k.a. a "Mail eXchange" record. An MX record is just a standardized directory listing that tells email servers where to deliver your email. Related, an SPF record tells email servers who is authorized to SEND your email.



You maintain these, and other, records on a DNS server. A DNS server tells the world things like "To deliver @Yahoo.com email, the first of several servers to try is "a.mx.mail.yahoo.com" which is reachable at internet address 67.195.168.31".



SMTP, "Simple Mail Transfer Protocol", refers to the standardized way to format and send email. An SMTP SERVER is a server that can accept email, and "do something with it". For a small company, a single server will handle everything from receiving SMTP connections to storing your inbox. For a big company, a dedicated "SMTP server" might receive email, check it for spam and malware, then forward it on to another server for storage and retrieval.



POP (POP3), "Post Office Protocol", refers to one of the two publicly standardized ways to talk to your email server. A POP SERVER is a server that lets you access your mailbox, and of course that server can do all the other email stuff too, or it can be dedicated to just letting you access your mailbox. The other major public standard is IMAP4, and the private standard that has more or less "won" is ActiveSync, which is used to connect to Microsoft Exchange email servers. POP3 is the most basic, ActiveSyc the most powerful. These are all used by programs. Many email servers can also be used with a web page, but those are all server specific.



So, let's say I am using Outlook Express. I write up an email for "[e-mail]" and hit "Send". Outlook Express then contacts my email server using SMTP, proves I am allowed to use that server for email, and gives it my email. (The sole reason for having the SMTP server involved is to prove your allowed to send email. You can actually send things directly, but your email will nearly always be rejected by the receiving server then.)



The SMTP server then looks up the MX entry for the "@CompanyName.com" part, and sees that a server named "abc.mail.CompanyName.com" handles incoming email, and that it's address is "123.45.67.89".



The SMTP server then tries to connect to 123.45.67.89 using the SMTP protocol. If abc.mail.CompanyName.com accepts the connection, it then is asked whether there's a mailbox for Bob, the part BEFORE the @ in "[e-mail]". Assuming the mailbox exists and is allowed to receive email, abc.mail.CompanyName.com signals that it will accept delivery, and delivery is made.



Assuming abc.mail.companyname.com is a complete email server, it processes the mail and places it in Bobs inbox. Bob then connect's to his inbox through web, POP3, IMAP4, or ActiveSync (depending on the server and the device used to connect) and is able to view/retreive his email.

Answer 2

SMTP is used to send mail to a mailserver. POP and IMAP are used to retrieve mail from the mailserver; also the Web can be used directly sometimes to retrieve mail (or it may use IMAP behind the scenes).



Nowadays everyone uses the Internet so mail mostly goes directly from the sender's server to the recipient's server, rather than going through gateways between different networks like bitnet and uucp like in the old days.

You can send direct to the recipient's server from your desktop (I often do, for testing), but there are 3 problems - your ISP may block port 25 as a virus risk, the recipient may mistrust your address in a spam scoring scheme, and if the recipient's server is busy or the recipient's mailbox is full, the mail will not be delivered. Using an outgoing server ensures that the message is automatically retried if it fails for some transient reason. It also gets it tagged with appropriate SPF and domainkey headers so that hopefully the recipient's anti-spam software will trust it.



Mailservers negotiate capabilities using SMTP or ESMTP protocol. See RFCs for details. E.g., if both servers support it, mail may be encrypted using TLS during transport. Most internet protocols are defined in a series of RFCs stored at ietf.org and other sites

Answer 3

you need to call your server provider to have your pop/ smtp server. they have all the learning so which you will establish your outlook show. you will save on getting errors in case you dont enter the best pop/smtp server and you are going to be able to't deliver/ acquire email utilising outlook show

Answer 4

Great replies, just what I was searching for.