Someone added me the other day about the Unusual I was selling about a month ago and I was like...why is this guy just now asking me? I closed the trade on Outpost when I was finished so I didn't understand how he even found it, I just told the guy he was too late and wished him luck
After some thinking I went to bazaar.tf and found that I'd put the trade up there too and completely forgot about it afterwards, and those trades apparently don't expire
There were 3 offers that I never saw until then, fortunately they were all terrible
If they arent any of the wanted crates (Salvaged, #60) or any of the crates on the market that are more than 10 cents, then just delete them.
No body is going to trade anything for them unless they are new to the game and think crates are useful.
Some people will take certain crates for free if they're planning on doing some big unboxing sprees, but yeah I just keep like 1-2 crates of each series just in case I ever feel like unboxing something for laughs and delete the rest