Moronic Mail Autoresponders (A FAQ From Hell)

This FAQ is first and foremost a classic example of trying to be cute while completely alienating the intended audience. I wrote it that way (including this paragraph :-) and now I'm too lazy and/or overworked to fix it. Be patient with all the sarcasm and, uh, "attitude"; there really is some useful technical stuff here.

Table of Contents

• What? or An introduction to moronic autoresponders
  • More fun: Annoying bounce messages
  • Where should the autoresponse/bounce go?
  • Corollary: Useful autoresponders
• Where to get yours
• Useful links
• Appendix: Sharing this useful resource with others

What? or An introduction to moronic autoresponders

"I use this nifty email program (which typically isn't even free software) and look, it allows me to send autoreplies like this one. I just wanted to say 'egads'. Thank you for listening."

Do I look like I care?

"Your mail has been delivered to my mailbox and I will read it as soon as I can."

Astonishing. Are you sure it was really meant for you? If your mail system is so unreliable that delivery of a message is considered a major event, you should be sending this notification to your postmaster, not to me. (If you use some buggy proprietary mail system inside your company, such as cc:Mail or MS Exchange, I can understand that delivery of a message is considered special. But that's still your problem, not mine.)

Normally, I would expect a bounce if it wasn't delivered. And/or am I supposed to believe that you normally don't read your mail?

"A client of ours subscribes to our r4d k00l newbie mail service and you sent him a message, so we thought that would make it okay for us to spam you. Perhaps we'll be selling your address to a company which specializes in sending unsolicited commercial email, too."

Eat my shorts. This is so obnoxious. And do you think they rate-limit this dreck? No, you get one "friendly reminder" for each message you send to this person.

Here's a (reassuringly short, for now) list of domains which do this in case you would like to block their notices:

mailpush.com

This is available as a separate text file, too. Click here to view and/or download: autoresponder-spammers.txt

(I would appreciate help with locating other domains which should be listed here. Please get in touch if you have that sort of information.)

I was also recently exposed to a service whose user documentation suggests you spam all your friends with an ad for this likewise r4d k00l new email feature you just got subscribed to so they can join the fun, too. It probably makes sense to respond to this kind of stuff with a spam complaint to the ISP of the user in question ...

"I am out of the office and will be back and read my mail on Friday the 13th."

This is annoying under the following circumstances:

• You never knowingly sent mail to this guy in the first place.
• The response contains no trace of your original message, so there's no way to tell what this is in response to.
• It gets sent to a mailing list, or you get it apparently in response to something you sent to a mailing list. See below for more on this fascinating topic.
• You receive a big batch of these notices, all from the same address.

It should be easy to deduce the following:

• A good autoresponder should never reply to mailing list mail. (Just think what would happen if two morons signed up to the same mailing list at about the same time, and their email autoresponders started bombing each other via the list. It's a spectacular, but not very pretty sight, for anyone on the mailing list.)
• A good autoresponder should always contain information about the message it's responding to. Ideally, the Subject header of the response should preserve at least part of the original Subject (perhaps with a prefix such as Autoresponse:) and the In-Reply-To and/or References: headers (see footnote) should contain the Message-Id of the message it is responding to.

While we're at it, here are a few more rules which aren't really specific to this particular case:

• Autoresponses should always contain the header

  	Precedence: junk
  

  Notice the spelling of "prec-e-dence". In particular, count the number of n:s (and a:s and s:es, if you're totally agraphic and/or from the United States). This will prevent well-tempered mail programs from generating bounce messages for these. If the recipient can't be reached, the autoresponder message is simply discarded.
• Autoresponders should take care to not respond to bounce messages (or mailing list messages, or other well-behaved autoresponders). A good thing to check against is the presence of that same Precedence header, and if its value is junk or bulk or list, don't respond.
  (For what it's worth, the meaning of the Precedence header in practice is that it affects Sendmail so that messages identified as less important get moved back in the queue under high load. On today's machines, that kind of load would be the exception rather than the norm. Those three values plus special-delivery are the only ones which have any meaning to Sendmail. first-class is also nominally recognized, but is equal to the case of no Precedence header. [If other MTAs have different semantics for this header, that would be a serious issue, and worth including here. If you have information about other systems, please let me know.])
• The documentation for Procmail contains a good regular expression for other things to watch out for (look for ^FROM_DAEMON. If you don't read regular expressions, you'll need serious help.)

"In an effort to avoid receiving spam, I ask you to key all your mail to me using the following secret word in the Subject: line: xyzzy"

This is barely tolerable if the autoresponder is otherwise set up correctly, but typically, you have some or all of the problems listed above (multiple notices, responses to mail you didn't particularly want to send to this person in the first place [perhaps you sent them to a mailing list], no trace of what the autoresponder is responding to).

More fun: Annoying bounce messages

"Your message to [email protected] could not be delivered because this user doesn't exist at phish.org"

Great, I never sent mail to Phred. Probably I never even sent anything to anyone at phish.org. Moreover, in the body of the bounce, we find a message I sent to a mailing list some time ago. But I can't do anything about this -- I didn't subscribe Phred, I don't know where he moved, I can't unsubscribe him, and frankly <blink>I don't care</blink> whether he gets this list or not.

This is a frequent configuration error with mailing lists (actually, it's a bug, dammit, not a configuration error). The list should set the envelope sender on outgoing mail to the list's owner (typically an alias like owner-list@site or list-request@site) so that s/h/it can take care of unsubscribing illegal addresses etc. without interfering with normal list operation. (By the way, a unique envelope sender also makes it much more convenient to unambiguously determine whether a message arrived via the list or perhaps as a private personal BCC.)

"The address [email protected] is not known to the program which handles mail for mail.site.org. Please get in touch with [email protected] if you think that's strange."

This is a problem with older versions of Post.Office and I believe Netscape's mail server. The bounce includes a lengthy explanation for the newbie postmaster about what could be wrong. But why is that being sent to the person whose message is not getting through?

I use postmaster just as an example here, although it's typical for this error to occur on the postmaster address.

For what it's worth, the postmaster address must work properly for every system which is handling mail on the Internet. See RFC822.

If you get one of these, it's reasonable and responsible to look up the domain in question in whois and mail the administrative contact(s) for the domain about this problem (as well as possibly the technical contact and the upstream provider).

Incidentally, RFC2142 lists some standard addresses besides postmaster which should be implemented at modern sites. This codifies e.g. webmaster as the standard address for responding to problems with web pages, abuse for spam complaints, etcetera.

"The address [email protected] is not known to the program which handles mail for mail.site.org. Please get in touch with [email protected] if you think that's strange."

A variant of the previous case. This would be funny if it wasn't so totally technically inept and, well, moronic.

mail.site.org: "551 <[email protected]> ... we do not relay"

We're not attempting to relay, we're attempting to get in touch with your freaking local postmaster. See previous cases.

"MS Exchange could not deliver mail to Administrator 983.0.0.9 ybpnyubfg 917.45.986.14 njnl.yvatfbsg.sv njnl 90.1.2.3 urp barf vomit"

You would receive this from a domain you have never heard about, but by examining headers in the bounced message and querying DNS, you find that you tried to mail not one but two users in a domain which this machine is MXing for. But do you think you are entitled to know which one is undeliverable? Nooo. It just reports which end point it couldn't reach. This is basically the same as the Friday the 13th example, although it's much more annoying because this time, you really knowingly tried to mail someone, and it didn't work out, and now, you'd probably like to know who you tried to contact, so you can e.g. call them on the phone instead.

I have $5 here which says, if you tried to mail a user in a domain and Cc: the postmaster, and get this response, the address which bounced will be the postmaster one.

Where should the autoresponse/bounce go?

Meanwhile, the fun little chart which comes with formail is a reasonable approximation (if you look at the chart which describes the behavior with the -rt option!) The documentation isn't very explicit about it, but it's a slighly whimsical but pragmatic compromise between obeying the letter of the various standards out there and what works in practice.

For what it's worth, at least one fairly knowledgeable person insists that the envelope sender of whatever triggered the autoresponder should be the recipient for all automatically generated mail. (Keith Moore in comp.mail.mime, August 1999.) I happen to think it's a violation of RFC822, but it's a somewhat complex issue.

Corollary: Useful autoresponders

"I am extremely overworked, and will probably not be able to respond within what is considered a normal time frame (something like 3 days). I'll hopefully be able to get back to you after Christmas 2003."

Okay, we'll know to wait patiently for a reply from this guy. His autoresponder should not send more than one of these notices to the same address in, say, a week. And did I mention it should not respond to mailing list mail?

"Thank you for contacting the Department department of So And So, Inc. We're busy beavers here, but rest assured that we are dealing with your complaint/whatever. We don't usually send replies if it's a matter of a simple bug report or something; we simply fix the bug and that's it. If a reply is warranted, our staff will get back to you."

This tells you, essentially, that they will deal with the matter and not send you a personalized reply. This automatic reply (frequently affectionately referred to as "ignorebot") will do. This is pretty much the standard you get nowadays when you send a spam complaint or a service request to an ISP, for example.

The autoresponder might also tell you something about the type of information they will need in order to be able to resolve your issue, so you can follow up with this information if you didn't include it in your original message. Perhaps they will also issue you a ticket number to make it easier (kind of) for you to get directly in touch with the staff member who is dealing with your problem report if you need to follow up.

Where to get yours

In the future, this section should probably be self-contained, and contain information about

• MUAs which offer autoresponder services
• MDAs which offer autoresponder services
• MTAs which offer autoresponder services
• Other programs which offer autoresponder services
• Other services which offer autoresponder services (such as Hotmail-type services [I don't think Hotmail has autoresponders though])

Useful Links

For now, this is basically cannibalized out of my bookmarks file.

The following sites should be interesting:

Dan Bernstein's site

There's a good annotated index of mail header fields and recommendations for their use, with pointers to RFCs where available. Definitely bookmark stuff.

The Internet Mail Consortium

A bit too much of "something for everyone" but the information you want is probably there somewhere.

Eli the Bearded's Mail Addressing FAQ

Tangential to the topic of this FAQ, but worth a look for other reasons.

Dmoz: Computers: Internet: Protocols: Mail

... and perhaps also Servers: Mail: Autoresponder Services

I have a bigger link collection as part of the Procmail FAQ I maintain.

The use of the In-Reply-To and References headers is explained somewhat on the Bernstein pages. There are also practical usage notes on a good number of other header fields.

Sharing this useful resource with others

The same goes for anyone else who needs this information.

However, you are not allowed to charge for this information, or claim that you wrote it. Because I did.

If you link to this page, please use this "official" URL instead of whatever it is that your moronic browser wants to make you think you are currently viewing:

http://www.iki.fi/era/mail/autoresponder-faq.html