I've lots of emails in my spam with the title "Undelivered Mail Returned to Sender"(My site was hacked and is sending out trash mails that got bounced back to my Gmail).
While I was trying to inspect these spams I noticed this behavior of Gmail search that I was never aware of:
If I search "undelivered" then all the emails with this subject will be brought up:
But if I search only part of the word like "undeliver" or "undeliv" there will not be any results:
Is this intended? When I try to search in Gmail should I always search the whole word instead of only part of it?