Jeremy Phillips

When you place an online order that is… I’ve gotten three shipping confirmations over the last year or so, all going to the same Jeremy Phillips in California. How Jeremy in California could mistake my e-mail address (jeremy at phillfam.com) for theirs is something I don’t know. It’s pretty funny though.

**** This is a post-only message. Please do not respond. ****

Dear JEREMY PHILLIPS,

This ship notification is being sent to you by the U.S. Postal Service® at the request of UNCUT MOUNTAIN SUPPLY. If the “Shipped To” address information is not correct, please contact the Shipper.

A package with a Click-N-Ship® label created on usps.com containing the following information is scheduled to be shipped on 08/14/2009.

From:	Shipped to:
UNCUT MOUNTAIN SUPPLY UNCUT MOUNTAIN SUPPLY 1518 W 13TH ST THE DALLES OR 97058-3708	JEREMY PHILLIPS Address Removed PMB #Removed City Removed CA Zip Removed

Type of Service: Delivery Confirmation™
Label Number: Removed

To check on the delivery status of your package, please go to Track and Confirm at www.usps.com.

Thank you,
United States Postal Service®

**Please do not respond to this email. Any reply will not be received by the USPS or the shipper. This email was sent to you at the shipper’s request to notify you that the information above has been electronically sent to the USPS.

I was discussing this with a couple of my team members at work the other day and was surprised to find that nobody had ever heard of Local Mail Transport Protocol (LMTP). LMTP is a derivative of SMTP. LMTP is designed as an alternative to normal SMTP for situations where the receiving side does not have a mail queue, such as a mail storage server acting as a Mail Delivery Agent. This is desirable since a mail storage server should manage only its mail store without having to allocate more storage for a mail queue. This is not possible with SMTP when there are multiple recipients for a mail message. SMTP can only indicate successful delivery or failure for all or none of the recipients, creating the need for a separate queue to handle the failed recipients. LMTP, on the other hand, can indicate success or failure to the client for each recipient, allowing the client to handle the queueing instead. The client in this case would typically be an Internet-facing mail gateway. LMTP is not intended for use over wide area networks.

LMTP is an application layer protocol, which runs on top of TCP/IP.

An LMTP conversation uses the same commands as an ESMTP conversation with the following exceptions:

• ESMTP’s EHLO verb is replaced with LHLO.
• LMTP should not listen on port 25.
• ESMTP requires a single status for the entire message body. LMTP requires a response for each previously successful RCPT command. That is, in case of multiple recipients, after the body of the message has been transmitted LMTP can still fail for some recipient and succeed for the others. That way, LMTP can fail if a user is over quota without the burden of generating Bounce messages.

The key difference is that LMTP will reject a message if it is not immediately deliverable to its final destination. This removes the need for a mail queue. For this reason, one is not supposed to run an LMTP server on the TCP/25 port.

• RFC 2033 — The Local Mail Transfer Protocol

Reading the New York Times Article “Can’t Open Your E-Mailbox? Good Luck” I find tales of woe like this one:

Discussion forums abound with tales of woe from Gmail customers who have found themselves locked out of their account for days or even weeks. They were innocent victims of security measures, which automatically suspend access if someone tries unsuccessfully to log on repeatedly to an account. The customers express frustration that they can’t speak with anyone at Google after filling out the company’s online forms and waiting in vain for Google to restore access to their accounts.

Tom Lynch, a software entrepreneur who lives near Austin, Tex., discovered early last month that he had been locked out of both Gmail accounts he used; he had no idea why. He received boilerplate instructions for recovering his accounts that did not apply to his particular circumstances, which included his failing to maintain a non-Gmail e-mail account as a back-up. He said it took him four weeks, including the use of a business directory and talking with anyone he could find at Google, before he succeeded in having service restored.

With my e-mail services provided by my server in my house, these are things I’ll never have to worry about.

We’ve already covered SMTP, here is how to test POP3 & IMAP with telnet.

POP3
telnet mail.domain.com pop3
+OK Hello there.
user user@domain.com
+OK Password required
pass <password>
+OK
list
1 1024
2 2944
3 99456
.
dele 2
+OK
quit
Connection closed by foreign host

IMAP
telnet mail.domain.com imap
* OK Microsoft Exchange Server 2007 IMAP4 service ready
1 LOGIN user@domain.com <password>
1 OK LOGIN completed.
1 SELECT Inbox
* 566 EXISTS
* 566 RECENT
* FLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent)
* OK [PERMANENTFLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent)] Permanent flags
* OK [UIDVALIDITY 8914] UIDVALIDITY value
* OK [UIDNEXT 42593] The next unique identifier value
1 OK [READ-WRITE] SELECT completed.
4 LIST ” ” “INBOX”
4 OK LIST completed.