I get one spam mail after another.
I get so much spam it's driving me insane.
Emails from Koichi are always found in the junk mail folder. I wonder why.
When you have troublesome (迷惑) mail, you have mail you don't want. This is known as spam, spam mail, or junk mail. On a more technical level it's unsolicited mail.
The reading comes from 迷惑, so if you know that you know this (and then this vocab word won't be unsolicited as well!)