No longer mortal man.

In fact the apostrophe was not limited to any particular season, as now
to the morning alone; indeed they used it on gloomy, nay, on the most
lamentable occasions; in Euripides, Polynices ends his life with the
words,

Joy with you! for the darkness closes on me.

Nor was it necessarily significative of friendliness; it could express
hatred and the determination to see no more of another. To wish much joy
to, was a regular form for ceasing to care about.

The modern use of the word dates back to Philippides the dispatch-runner.
Bringing the news of Marathon, he found the archons seated, in suspense
regarding the issue of the battle. 'Joy, we win!' he said, and died upon
his message, breathing his last in the word Joy. The earliest letter
beginning with it is that in which Cleon the Athenian demagogue, writing
from Sphacteria, sends the good news of his victory and capture of
Spartans at that place. However, later than that we find Nicias writing
from Sicily and keeping to the older custom of coming to business at once
with no such introduction.

Now the admirable Plato, no bad authority on such matters, would have us
reject the salutation Joy altogether; it is a mean wish, wanting in
seriousness, according to him; his substitute is Prosperity, which stands
for a satisfactory condition both of body and soul; in a letter to
Dionysius, he reproves him for commencing a hymn to Apollo with Joy,
which he maintains is unworthy of the Pythian, and not fit even for men
of any discretion, not to mention Gods.