It sounds like you have an interesting secretary. Do you have a strata manager?
You say that the secretary passed and registered the by-law, was the by-law approved by the owners at a general meeting? The secretary can’t approve a by-law by themselves so if that is what they did, the by-law would not be valid. However, if it has been registered you need to get on to it because after 2 years it may be hard to challenge.
If I were you while this purported by-law is in place I would just ignore it, as you say there is no law preventing email between people and if it went to a Tribunal it would be likely to be struck down, depending on how it is drafted.