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Unicode::IMAPUtf7 - Perl extension to deal with IMAP UTF7


  use Unicode::IMAPUtf7;

  my $t = Unicode::IMAPUtf7->new();
  print $t->encode('Répertoire');
  print $t->decode('R&AOk-pertoire');


  print Unicode::IMAPUtf7::imap_utf7_encode('R�pertoire');
  print Unicode::IMAPUtf7::imap_utf7_decode('R&AOk-pertoire');



IMAP mailbox names are encoded in a modified UTF7 when names contains international characters outside of the printable ASCII range. The modified UTF-7 encoding is defined in RFC2060 (section 5.1.3).



Returns a new instance of a Unicode::IMAPUtf7 object.


Returns the modified UTF7-text for a string in UTF8.


Returns the decoded string into UTF8 data.


imap_utf7_encode: returns the modified UTF7-text for a string in Latin1.

imap_utf7_decode: returns the decoded string into Latin1 data.

These functions may disappear in some later version. Please update with the new OO and UTF8 scheme. See Unicode::String for conversion functions between Latin1 and UTF8.

RFC2060 - section 5.1.3 - Mailbox International Naming Convention

By convention, international mailbox names are specified using a modified version of the UTF-7 encoding described in [UTF-7]. The purpose of these modifications is to correct the following problems with UTF-7:

1) UTF-7 uses the "+" character for shifting; this conflicts with the common use of "+" in mailbox names, in particular USENET newsgroup names.

2) UTF-7's encoding is BASE64 which uses the "/" character; this conflicts with the use of "/" as a popular hierarchy delimiter.

3) UTF-7 prohibits the unencoded usage of "\"; this conflicts with the use of "\" as a popular hierarchy delimiter.

4) UTF-7 prohibits the unencoded usage of "~"; this conflicts with the use of "~" in some servers as a home directory indicator.

5) UTF-7 permits multiple alternate forms to represent the same string; in particular, printable US-ASCII chararacters can be represented in encoded form.

In modified UTF-7, printable US-ASCII characters except for "&" represent themselves; that is, characters with octet values 0x20-0x25 and 0x27-0x7e. The character "&" (0x26) is represented by the two- octet sequence "&-".

All other characters (octet values 0x00-0x1f, 0x7f-0xff, and all Unicode 16-bit octets) are represented in modified BASE64, with a further modification from [UTF-7] that "," is used instead of "/". Modified BASE64 MUST NOT be used to represent any printing US-ASCII character which can represent itself.

"&" is used to shift to modified BASE64 and "-" to shift back to US- ASCII. All names start in US-ASCII, and MUST end in US-ASCII (that is, a name that ends with a Unicode 16-bit octet MUST end with a "- ").

For example, here is a mailbox name which mixes English, Japanese, and Chinese text: ~peter/mail/&ZeVnLIqe-/&U,BTFw-


Please report any requests, suggestions or bugs via the RT bug-tracking system at or email to bug-Unicode-IMAPUtf7\ is the RT queue for Unicode::IMAPUtf7. Please check to see if your bug has already been reported.


Copyright 2001-2004

Fabien Potencier,

This software may be freely copied and distributed under the same terms and conditions as Perl.


perl(1), Unicode::String.

1 POD Error

The following errors were encountered while parsing the POD:

Around line 12:

Non-ASCII character seen before =encoding in '$t->encode('Répertoire');'. Assuming UTF-8