What to use when no AUTH=

[Patrick Welche]

When connecting to imap servers with sasl, I thought the plan was to
parse the capability string and add any AUTH= to the mechlist. This
was fine for cyrus :) and UW, but pointing my code at Courier, I
get

S: * CAPABILITY IMAP4rev1 CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT
...

Now, I am missing something, because cyrus' imtest connects with no problem.
What mechanism is it using? What is the right thing to do?

Cheers,

Patrick