Has he given a reason why he won't accept an electronic money transfer? The only reason I can think of is, if he endorses the back of a cheque it can be deposited into someone elses account (a girlfriends?) Is there a possible tax reason why he'd do this? Maybe he wants to write off the full expense amount, instead of a portion.
Does he have an accountant? Offer to send him reimbursements through his representative. It'll provide a cushion for him to protect his super secret vault of riches, and maybe it'll appeal to his suspicious nature.
Seriously though, it sounds like he's just trying to make life difficult for you. If someone doesn't accept an e-transfer the money goes back into your account after 30 days, right? I'd tell him he can take it or leave it, send it 3X so he has 3 months of opportunity, and keep a record of having tried to pay him. I'd flat-out say that if he refuses it 3X I'm going to keep it, too. Then just throw it in a savings account in case you get ordered down the line to pay him by some other means. I don't know how it works from a legal standpoint, but when someone is refusing payment how long can you be expected to keep trying?
Also, his argument about compromised bank account info is BS. If he's uncomfortable giving you HIS bank info... why on earth would you give him YOURS? (Since routing and account numbers are emblazoned on every check.) Tell him it's a stupid double standard for him to conceal his bank info while he expects you to willingly fork yours over. And to stop being an idiot and accept the EFT like a normal person. :grin:
Some people just enjoy being difficult! DH pays all his bills online, including child support. But in the case of his Ex, the bank prints a paper check and mails it to her. A couple of times the check literally got lost in the mail. The second time it happened, DH offered to pay her via paypal. Easier for everyone, right? She doesn't even have to go to the bank anymore.
Her response, "let me do some research to make sure there aren't any hidden fees and I will get back to you." He never heard about it again. We still joke about all of those "hidden fees" that don't apply to anyone on paypal, but her.
So she continues to receive a paper check every month...and go to the bank...every month. One time he initiated a check for reimbursement of medical expenses and she never cashed it. He got a notice from the bank that his account was being refunded. Guess it wasn't that important to her.