Is 'F7->F8' allowed as a name of IMAP folder?

[Matej Cepl]

Hi,

looking at the bug 377271 at Red Hat bugzilla (https://
bugzilla.redhat.com/show_bug.cgi?id=377271) I get weird feeling that the
problem is not on the side of our software, but when I tried to find the
answer in RFC 2060, I got totally lost and I cannot find the answer. When
looking at 5.1 it looks like anything (except for / \ . ~ ) could be used
in a folder name. Is it correct? Can I use 'F7->F8' as an IMAP folder
name?

Thanks for any reply,

Matěj Cepl

[Matthias Hanft]

Matej Cepl wrote:
>
> Can I use 'F7->F8' as an IMAP folder
> name?

After using many POP and IMAP servers and clients in the last
20 years, I use only letters and digits and "-" for my folder
names. There is (or was, or will be) always the _one_ software
which cannot deal with other special characters in the folder
name. So, why should you intentionally prepare some trouble
for yourself which comes out in some years?

Use just "F7-F8", and it will work still in 100 years...

Matt

[Matej Cepl]

On Mon, 12 Nov 2007 11:47:04 +0100, Matthias Hanft scripst:

> After using many POP and IMAP servers and clients in the last 20 years,
> I use only letters and digits and "-" for my folder names. There is (or
> was, or will be) always the _one_ software which cannot deal with other
> special characters in the folder name. So, why should you intentionally
> prepare some trouble for yourself which comes out in some years?
>
> Use just "F7-F8", and it will work still in 100 years...

you missed the point -- it is not for me, but for my reporters.

Matěj

[Mark Crispin]

On Mon, 12 Nov 2007, Matej Cepl wrote:
> looking at the bug 377271 at Red Hat bugzilla (https://
> bugzilla.redhat.com/show_bug.cgi?id=377271) I get weird feeling that the
> problem is not on the side of our software, but when I tried to find the
> answer in RFC 2060, I got totally lost and I cannot find the answer.

For what it's worth, RFC 3501 is the current specification.

> When
> looking at 5.1 it looks like anything (except for / \ . ~ ) could be used
> in a folder name. Is it correct? Can I use 'F7->F8' as an IMAP folder
> name?

The simple answer to your question is "yes."

The more complex answer:

A mailbox name may contain any character with codepoint value between 0x01
and 0xff. However, some codepoints are impractical: non-graphics
(0x01-0x1f and 0x3f) and codepoints that require special quoting to get
around IMAP syntax rules (0x22, 0x25, 0x2a, 0x5c). 0x25 and 0x2a are
particularly troublesome in this regard.

Servers ARE permitted to establish their own rules and restrictions.
Many servers use codepoint 0x2f (and a few use 0x2e or even 0x5c) as a
hierarchy delimiter. You need to be aware of that server's rules.

Certain other codepoints (notably 0x20, 0x3a, 0x3b, 0x3c, 0xe3, 0x7b,
0x7d, 0x7e) have special meanings for some servers.

Last, but not least, 0x26 and 0x23 have specification-defined conventions
in IMAP and thus care must be taken.

IMHO, the advice to stick to alphanumerics and hyphen is good advice.
Many other characters should work, probably will work, but there is always
the server out there that won't let it work.

What this all means that that your F7->F8 name will probably work OK with
most servers. The only server that I know of where it won't work is one
that very very few people will ever encounter.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.

[Matej Cepl]

On Mon, 12 Nov 2007 12:24:13 -0800, Mark Crispin scripst:

> What this all means that that your F7->F8 name will probably work OK
> with most servers. The only server that I know of where it won't work
> is one that very very few people will ever encounter.

Thanks a lot. That's exactly what I needed.

Matěj