On the left sidebar, you can click the "Search" link, to search for messages or contacts.
You can enter a word (or multiple words) that appears anywhere within the message you want to locate. You can however use advanced queries described below.
Simply entering what you are looking for is enough in most cases, but sometimes you want to be more specific, or need to be more specific (if you see an error message like "There are too many results, please enter a more specific query")
from:johnsmith to find all the messages from JohnSmith
to:johnsmith to find all the messages to JohnSmith
in:inbox to find all the messages sent to you (in your inbox, it's the same as entering to:YourNick)
in:outbox to find all the messages sent by you (in your outbox, it's the same as entering from:YourNick)
from:johnsmith meeting to find all the messages from JohnSmith, that have the word "meeting" anywhere
from:johnsmith meeting friday to find all the messages from JohnSmith, that have the words "meeting" and "friday" anywhere
meeting friday from:johnsmith (same result as above) - to find all the messages from JohnSmith, that have the words "meeting" and "friday" anywhere
in:outbox meeting friday to find all the messages sent by you (in your outbox), have the words "meeting" and "friday" anywhere (this is actually the same as entering from:YourNick meeting friday)
from:john* meeting to find all the messages where the sender field (from...) starts with "john", e.g. "john", as well as "johnny" or "johnsmith", that have the word "meeting" anywhere
from:*hn meeting to find all the messages where the sender field (from...) ends with "hn" like "john", that have the word "meeting" anywhere
to:*@someserver.com to find all the messages sent to emails at anything@someserver.com
from:*a* to find all the messages from users whose nick (or email address) has the letter "a" somewhere
from:!john meeting to find all the messages not from "John", that have the word "meeting" anywhere
from:john !meeting to find all the messages from "John", that does not have the word "meeting" somewhere
from:!*smith* meeting to find all the messages not from anybody whose nick (or email address) starts or ends with "smith", that have the word "meeting" anywhere
Found messages are always sorted by date, that is, newest messages are at the top
If you see an error: "There are too many results, please enter a more specific query", try using one of the operators described above. Instead of entering simply "dinner" enter "from:john dinner" (if you know the message is from John).