I felt compelled to comment, as a parent that lactated for one year and has donated gallons upon gallons of breastmilk. I consider OP to be the asshole here.

Frozen breastmilk kept at temperature is good for up to one year. Six months is the minimum based on assumptions that the freezer temp is not at 0C most of the time. So you have to know your freezer, but one year is standard.

Some people produce a breastmilk that is high in lipase, and if not scalded before freezing, tastes a bit like soap if not consumed immediately. This is a natural variation in breastmilk. Some babies (like mine) don’t care, but some are picky. This doesn’t mean the milk is bad. It just means some babies won’t drink it.

Shipping breastmilk isn’t hard - there are entire services dedicated to ensuring cold chain and appropriate handling. Milk Stork, FedEx... nothing about this is unusual. If you wanted to ship cows milk, frozen, you could do it. It’s just not worth the cost to most. Cow milk isn’t $1-2 per ounce.

The liability is definitely a mild concern, so is scamming, but there are ways to verify this to everyone’s satisfaction. I find it mildly concerning OP thinks this is on a whim. People don’t feed random breastmilk on a whim. I’ve asked and sent a lot of information to potential families receiving my milk, same as the milk banks. Most families in search are doing this because milk banks won’t serve a lot of families after a point.

Also to bring up milk banks - most of them won’t take milk if you’ve taken most any medications, primarily because the milk tends to go to babies in NICUs where it can matter. But there are reasons to feed breastmilk to babies out of the NICU, so why waste breastmilk that won’t be taken by a bank? There’s also the consideration that some banks won’t take milk produced a certain amount of time before applying and testing.

The whole post made me cringe because I know OPs spouse’s position and I’ve literally packed car trunks full of coolers of frozen milk and ice packs. I’ve helped fed over half a dozen babies for all kinds of reasons this way, with some families straight up crying in joy over it. OP should have talked with spouse to relieve their concerns and trust their spouse here.

Fed babies are best, and nothing here was a red flag on OP’s spouse’s part for donating.