Topic: SMTP server and POP connections

[chris snow]

Is it possible to setup the SME to receive email via SMTP AND POP?

Thanks,

Chris

[Nathan Fowler]

Nope, POP cannot receive incoming mail by design.  POP is used to deliver mail to the clients, SMTP is used to transmit the mail message to and from servers.  POP is a "push-only" type protocol, where SMTP is "bi-directional"

[Andy Parkinson]

Sorry to disagree  Nathan but POP isn't just used to deliver mail to the clients. POP can be used to collect mail for the SME server from the ISP. This is what the multidrop mail is. Pop is a pull only type protocol not push only. The server can receive mail by either POP or SMTP or both. When using SMTP to receive mail the transfer can be initiated by the mail server sending the mail or if using ETRN the sme will send an enhanced turn command to tell the isp's SMTP to turn around and send to the SME.  So back to Chris's original question-
"Is it possible to setup the SME to receive email via SMTP AND POP?" then the answer would be yes.

[Nathan Fowler]

Andy,
I was looking at it from a higher level.  In this case you mentioned above, POP is not sending mail, it is retrieving mail from an ISP and then delivering it to the local daemon which then processes and distributes the mail accordingly (whether to the SMTP daemon or the user mailbox itself)

I understood Chris's question as "I want to be able to receive mail on POP and SMTP".  This is a very vauge question, is he wanting to do it to bypass some type of Port 25 restriction placed on his network by his ISP?  I got out of that question that he was hoping that the functionality of SMTP was synonymous with that of POP, not that he wanted to use multidrop.

When I said it was push, I was referred to the server-view of it.  The client pulls the messages using POP3.  I'm aware of multipop capabilities, but I wasn't sure that's what Chris was wanting to do.

Either way, I do appreciate your response.  If what I said caused confusion, then I thank you for taking the time to clear any of that up.

Nathan

[chris snow]

Sorry for the confusion.

I posted the question because of a problem I had at a customer's site where the SME is setup to pick up email from their ISP using POP accounts - which works very well.  However, a couple of days ago the ISP had major problems with their email servers.  As my customer's business is dependant on emails, it pretty much brought them to a grinding halt.

In light of the above, I am looking at ways of building some redundancy into the emails in the (unlikely) event of the ISP's mail servers failing again.  On the whole the ISP is very good and offer an excellent service (at a low cost) where they virus scan all incoming email.  

I was therefore thinking of using the ISP as the main MX record for email retrevial, but having a second MX record pointing to the SME server in the event of ISP mail problems.

My ISP has told me that this is possible and now that I know the SME can handle it, I will start getting it configured.  Anyone have any recommendations for DNS hosting companies?

Thanks for the feedback,

Chris

[Nathan Fowler]

I use http://www.worldwidedns.net , they're very cheap and reliable.  I host about 15 domains with them.  Update to DNS are almost instantaneous.

Nathan

[Kelvin]

Hi Chris,


>I was therefore thinking of using the ISP as the main MX record for email
>retrevial, but having a second MX record pointing to the SME server in the event
>of ISP mail problems

Hmm, this is an unusual perspective on this. I would have thought if your client's setup allows them to have an MX pointing to them at all (ie. not have to rely on multidrop, etc. and just use standard SMTP mail), you would have set it up so that the client's server becomes the primary MX while the ISP becomes the secondary MX. This way, mails get delivered to your client's server faster and it does not matter if your client's ISP's mail server go down -- as long as the DNS still points to your client's server as the primary MX, mails still gets there.

Kelvin

[chris snow]

Thanks for the recommendation.  I will give them a try.