![](https://secure.gravatar.com/avatar/a5bfb93c356aa0cb47ffa9a71caed502.jpg?s=120&d=mm&r=g)
Does the list support plus addressing? Google and O365 support plus addressing. This allows someone to subscribe as myself+lists@mycompany.com when their real email address is myself@company.com. The problem is that when they reply, or generate a new message, it may be held or rejected because it is coming from an address different than they subscribed with. I am aware of the hack at: https://wiki.list.org/DOC/How%20can%20I%20post%20from%202%20or%20more%20addr... However this does not appeal to the tinfoil hat crowd who thinks you are just going to sell both addresses. Nor do I want to explain to the masses this hack.
![](https://secure.gravatar.com/avatar/02cc25ec5c6cd5c6a65a6d94817fe815.jpg?s=120&d=mm&r=g)
Hello robertowenberendt@gmail.com. On Mon, 21 Mar 2022 14:01:58 -0000, you wrote:
Instead of using "Plus addressing", in most (if not all) mail programs it is possible to set up rules for messages coming from a certain source. This rule can sort messages from mailinglist1 in one mail folder, and messages from mailinglist2 in another folder.
Christian
--
Christian Buser, Hohle Gasse 6, CH-5507 Mellingen (Switzerland)
Hilfe fuer Strassenkinder in Ghana: https://www.chance-for-children.org
![](https://secure.gravatar.com/avatar/2d8b084fbf3bb480d8a3b6233b498f4f.jpg?s=120&d=mm&r=g)
On 3/22/22 3:23 AM, Christian via Mailman-Users wrote:
I think part of the thinking is that if a spammer gets hold of one address, you can filter it off and still use the account. The problem is that the spammer may well understand + hacking, and get back to the root address, so it doesn't really help.
-- Richard Damon
![](https://secure.gravatar.com/avatar/76d2087162db886899fb9d9ed42ba034.jpg?s=120&d=mm&r=g)
On 2022-03-22 at 03:23:29 UTC-0400 (Tue, 22 Mar 2022 08:23:29 +0100) Christian via Mailman-Users <luscheina@yahoo.de> is rumored to have said:
And sometimes users use plus addressing (or other related 'tagging' schemes) to support such rules.
Of course, that's not the business of a mailing list operator. We should assume that our users know what they're doing and that it isn't our business unless they need help.
-- Bill Cole bill@scconsult.com or billcole@apache.org (AKA @grumpybozo and many *@billmail.scconsult.com addresses) Not Currently Available For Hire
![](https://secure.gravatar.com/avatar/76d2087162db886899fb9d9ed42ba034.jpg?s=120&d=mm&r=g)
On 2022-03-21 at 10:01:58 UTC-0400 (Mon, 21 Mar 2022 14:01:58 -0000) <robertowenberendt@gmail.com> is rumored to have said:
Does the list support plus addressing?
What do you mean by that question???
"Plus addressing" is only relevant to final local delivery and in some cases to intra-realm bespoke mail routing. Address local-parts MUST NEVER be interpreted as anything but opaque nonces unless they are in "your" domains. Do not attempt to parse, validate, translate, or canonicalize local-parts in other people's domains.
A mailing list MUST NOT generically equate two local-parts in a non-local domain without the explicit permission of the users whose addresses are being equated.
Google and O365 support plus addressing.
That is not relevant to a mailing list not operated by Google or MS. Support for plus-addressing has been widespread for decades. If it isn't YOUR plussed address, it's just an address. The plus in the local part is none of your business. Do not touch it. You cannot know how an address owner is handling plussed addresses unless they tell you, and that does not mean unless their mail provider tells you.
This allows someone to subscribe as myself+lists@mycompany.com when their real email address is myself@company.com.
Yes. I do something similar and have for decades. Every list I subscribe to uses a different address, all of which ultimately deliver to mailboxes in the same IMAP account. I abandoned the '+' as a delimiter some years ago because of the bad habit of some mail handlers of trying to disassemble plussed addresses.
That is 100% the sender's problem. If they can't send and receive mail with the address they used to subscribe, they should never have used it to subscribe. It's fine to accommodate specific individuals' incapacity to use their addressing flexibility as designed.
If a MUA doesn't support sending mail with arbitrary plus addressing, it doesn't really support plus addressing. That includes webmail MUAs like GMail and MS365/OWA. Desktop MUAs have been supporting this since Eudora v1.0, so it's hardly a novel feature.
The only reason to do that is to accommodate individuals who specifically want it and/or who chronically send with a wrong address and so clearly need it.
The idea of a discussion mailing list 'selling addresses' is silly. Without significant customization any subscriber to a discussion mailing list using Mailman or similar tools can see the address of every person posting to the list. If one uses an email address in a public way for long enough, it will get to spammers. Even if you don't use it publicly, spammers may land on it with guesses and other users might typo their addresses to yours when giving it to others.
-- Bill Cole bill@scconsult.com or billcole@apache.org (AKA @grumpybozo and many *@billmail.scconsult.com addresses) Not Currently Available For Hire
![](https://secure.gravatar.com/avatar/baa72321ff7f0e9dd8a7ce2673cf7de6.jpg?s=120&d=mm&r=g)
On 3/21/22 8:01 AM, robertowenberendt@gmail.com wrote:
Does the list support plus addressing?
Yes and no.
I believe the more proper name for this is user+detail. I see "plus(ed) addressing" used more commonly more recently.
Yes, Mailman will happily accept user+detail addresses from subscribers.
No, Mailman itself won't treat user+detail@ and user@ as equal.
I am aware of the hack at:
This is what I've been doing for years.
However this does not appeal to the tinfoil hat crowd who thinks you are just going to sell both addresses.
There are a lot of things that don't appeal to people for one reason or another.
Nor do I want to explain to the masses this hack.
You have to make a choice.
Use separate addresses (and subscribe both) or don't, it's up to each individual.
There may very well be client side options too. E.g. configuring the MUA that when you are on a folder for a given mailing list that it uses a different source address when composing messages. Though this has it's own failure mode related to false positive / negatives. There might be an MUA option to change sender addresses based on destination addresses.
What is the lesser evil to you / your users?
-- Grant. . . . unix || die
![](https://secure.gravatar.com/avatar/02cc25ec5c6cd5c6a65a6d94817fe815.jpg?s=120&d=mm&r=g)
Hello robertowenberendt@gmail.com. On Mon, 21 Mar 2022 14:01:58 -0000, you wrote:
Instead of using "Plus addressing", in most (if not all) mail programs it is possible to set up rules for messages coming from a certain source. This rule can sort messages from mailinglist1 in one mail folder, and messages from mailinglist2 in another folder.
Christian
--
Christian Buser, Hohle Gasse 6, CH-5507 Mellingen (Switzerland)
Hilfe fuer Strassenkinder in Ghana: https://www.chance-for-children.org
![](https://secure.gravatar.com/avatar/2d8b084fbf3bb480d8a3b6233b498f4f.jpg?s=120&d=mm&r=g)
On 3/22/22 3:23 AM, Christian via Mailman-Users wrote:
I think part of the thinking is that if a spammer gets hold of one address, you can filter it off and still use the account. The problem is that the spammer may well understand + hacking, and get back to the root address, so it doesn't really help.
-- Richard Damon
![](https://secure.gravatar.com/avatar/76d2087162db886899fb9d9ed42ba034.jpg?s=120&d=mm&r=g)
On 2022-03-22 at 03:23:29 UTC-0400 (Tue, 22 Mar 2022 08:23:29 +0100) Christian via Mailman-Users <luscheina@yahoo.de> is rumored to have said:
And sometimes users use plus addressing (or other related 'tagging' schemes) to support such rules.
Of course, that's not the business of a mailing list operator. We should assume that our users know what they're doing and that it isn't our business unless they need help.
-- Bill Cole bill@scconsult.com or billcole@apache.org (AKA @grumpybozo and many *@billmail.scconsult.com addresses) Not Currently Available For Hire
![](https://secure.gravatar.com/avatar/76d2087162db886899fb9d9ed42ba034.jpg?s=120&d=mm&r=g)
On 2022-03-21 at 10:01:58 UTC-0400 (Mon, 21 Mar 2022 14:01:58 -0000) <robertowenberendt@gmail.com> is rumored to have said:
Does the list support plus addressing?
What do you mean by that question???
"Plus addressing" is only relevant to final local delivery and in some cases to intra-realm bespoke mail routing. Address local-parts MUST NEVER be interpreted as anything but opaque nonces unless they are in "your" domains. Do not attempt to parse, validate, translate, or canonicalize local-parts in other people's domains.
A mailing list MUST NOT generically equate two local-parts in a non-local domain without the explicit permission of the users whose addresses are being equated.
Google and O365 support plus addressing.
That is not relevant to a mailing list not operated by Google or MS. Support for plus-addressing has been widespread for decades. If it isn't YOUR plussed address, it's just an address. The plus in the local part is none of your business. Do not touch it. You cannot know how an address owner is handling plussed addresses unless they tell you, and that does not mean unless their mail provider tells you.
This allows someone to subscribe as myself+lists@mycompany.com when their real email address is myself@company.com.
Yes. I do something similar and have for decades. Every list I subscribe to uses a different address, all of which ultimately deliver to mailboxes in the same IMAP account. I abandoned the '+' as a delimiter some years ago because of the bad habit of some mail handlers of trying to disassemble plussed addresses.
That is 100% the sender's problem. If they can't send and receive mail with the address they used to subscribe, they should never have used it to subscribe. It's fine to accommodate specific individuals' incapacity to use their addressing flexibility as designed.
If a MUA doesn't support sending mail with arbitrary plus addressing, it doesn't really support plus addressing. That includes webmail MUAs like GMail and MS365/OWA. Desktop MUAs have been supporting this since Eudora v1.0, so it's hardly a novel feature.
The only reason to do that is to accommodate individuals who specifically want it and/or who chronically send with a wrong address and so clearly need it.
The idea of a discussion mailing list 'selling addresses' is silly. Without significant customization any subscriber to a discussion mailing list using Mailman or similar tools can see the address of every person posting to the list. If one uses an email address in a public way for long enough, it will get to spammers. Even if you don't use it publicly, spammers may land on it with guesses and other users might typo their addresses to yours when giving it to others.
-- Bill Cole bill@scconsult.com or billcole@apache.org (AKA @grumpybozo and many *@billmail.scconsult.com addresses) Not Currently Available For Hire
![](https://secure.gravatar.com/avatar/baa72321ff7f0e9dd8a7ce2673cf7de6.jpg?s=120&d=mm&r=g)
On 3/21/22 8:01 AM, robertowenberendt@gmail.com wrote:
Does the list support plus addressing?
Yes and no.
I believe the more proper name for this is user+detail. I see "plus(ed) addressing" used more commonly more recently.
Yes, Mailman will happily accept user+detail addresses from subscribers.
No, Mailman itself won't treat user+detail@ and user@ as equal.
I am aware of the hack at:
This is what I've been doing for years.
However this does not appeal to the tinfoil hat crowd who thinks you are just going to sell both addresses.
There are a lot of things that don't appeal to people for one reason or another.
Nor do I want to explain to the masses this hack.
You have to make a choice.
Use separate addresses (and subscribe both) or don't, it's up to each individual.
There may very well be client side options too. E.g. configuring the MUA that when you are on a folder for a given mailing list that it uses a different source address when composing messages. Though this has it's own failure mode related to false positive / negatives. There might be an MUA option to change sender addresses based on destination addresses.
What is the lesser evil to you / your users?
-- Grant. . . . unix || die
participants (5)
-
Bill Cole
-
Christian
-
Grant Taylor
-
Richard Damon
-
robertowenberendt@gmail.com