Hi John, > On 11 May 2018, at 18:02, John C Klensin <john-ietf@xxxxxxx> wrote: > > That said, I'm uncomfortable with using "=40" as a convention in > the middle of an address. First, there is nothing that supports > the idea of encoded octets in the middle of local parts and, as > you know, there is ample precedent for interpreting an equal > sign in a local part as an indication of a name-value setup. As far as the DMARC workaround for IETF mailing lists is concerned, the encoding is an implementation detail and might change in the future. Use of = is in fact configurable. The only requirement on encoding is that it should somehow be reversible. I published specific details because IETF is a technical community and people want to know details about IETF infrastructure. > We > haven't seen SMTPUTF8 addresses on the IETF list yet, but I > think there is a strong case to be made that, if we are going to > start encoding things, we should be encoding Unicode code points > (e.g., > "alexey\u'0040'example.com@xxxxxxxxxxxxxx" or > "alexey?utf8"?40?example.com@xxxxxxxxxxxxxx" > ) rather than inventing yet another new system. I don't think > that is a good idea, in part because I encountered an example in > the last 24 hours that tries to use encoded words to deal with a > non-ASCII local part (something the EAI WG considered and > rejected and that, if performed in transit, is non-conformant > with the SMTPUTF8 specs). Any encoding trick like the above (or > like just using "=40") is going to encourage that sort of > "innovation". Deploying EAI for IETF mailing lists would be a big undertaking in itself. We can cross this bridge when we need to cross it. > > With the understanding that I'm holding my nose while saying > this (because I have been happy to see the convention fade from > use), we already have a widely-supported and recognized > convention for this type of encoding and I wonder why those who > have been involved with this effort rejected it. That would be > to use > alexey%example.com@xxxxxxxxxxxxxx The short answer is that Henrik tries to use % and found that various software (including some non IETF mailing lists, if I remember correctly) was buggy and assigned some special meaning to % that made it unsuitable for our purposes. Best Regards, Alexey
