diff options
Diffstat (limited to 'pop3.c')
| -rw-r--r-- | pop3.c | 13 |
1 files changed, 8 insertions, 5 deletions
@@ -198,13 +198,16 @@ int pop3_getauth(int sock, struct query *ctl, char *greeting) /* * AUTH command may return a list of available mechanisms. - * if it doesn't, no harm done. Efficiency hack: most servers - * don't implement this, so don't do it at all unless the - * server advertises APOP with <> in the greeting line. This - * certainly catches IMAP-2000's POP3 gateway. + * if it doesn't, no harm done. + * + * APOP was introduced in RFC 1450, and POP3 AUTH not until + * RFC1734. So the < check is an easy way to prevent AUTH from + * being sent to the more primitive POP3 servers dating from + * RFC 1081 and RFC 1225, which seem more likely to choke on + * it. This certainly catches IMAP-2000's POP3 gateway. * * These authentication methods are blessed by RFC1734, - * POP3 AUTHentication command. + * describing the POP3 AUTHentication command. */ if (strchr(greeting, '<') && gen_transact(sock, "AUTH") == 0) { |