Bollocks they do 
Males can lactate - if they go it means they are producing prolactin and that means something is wrong somewhere. Some antipsychotic drugs for example increase prolactin levels.
So males can, technically, lactate, in the sense of producing a secretion from the mammary.
What males cannot do is produce a situation akin to female normal lactation. They do not have sufficient tissue nor can they produce enough. So a Male lactating is usually a symptom of a disease process or exogenous hormones.
To donate, you need a baby under a few months old and to be tested for various pathogens. The ‘quality’ of the milk is not tested.
Bear in mind that a woman taking hormones will likely be unable to donate - the advice is to pump and dump even with the morning after pill. A Male, taking hormones to produce abnormal, marginal lactation, would not be able to fovate, and would not be able to produce enough to donate.
File under ‘did ye, aye?’