Depositing check into current account via mail

I need to check my documents at home but we repatriated in July and still have our HSBC current account open. We have been waiting for DH's HMRC tax stuff for both tax years to be resolved (finally got deposited!!). However we got a cheque from Cigna (seriously late, we had given up on it) and it was mailed here to us in the US. Anyone ever deposited a cheque via mail?

My husband and I have deposited a few checks through the post on different occasions.  Our bank is not a common one and the closest branch is in a different town.  It has never been a problem except for one time a check has gone missing.  It could have gotten lost in the mail or maybe we never mailed it like we thought we did.

Maybe you could call someone at the bank to let them know you will be posting them a check to deposit, just so they are on the lookout for it.