In case you like the idea, this is how I sign my emails these days to gently educate whoever I happen to be emailing.

A mask might be appropriate if you're actively sneezing, coughing and infected but, otherwise, no.  See WHO Recommends against wearing a mask, or this, this, this or this for more.

See also:

"OK, you're probably thinking that doesn't make much sense, this crusade to vaccinate the entire species against a relatively standard respiratory virus, but that's just because you are still thinking critically."

-- from consentfactory.org.