I don't understand why this has become a trendy pet peeve to have now, at least 5 years after email ceased to be a relevant form of communication. If you care about email, you've already lost.
Overuse of automated out-of-office respondes does far more damage to the medium.
I get and send dozens of important emails a day. Why is email irrelevant?
"A May 2011 Pew Internet survey finds that 92% of online adults use search engines to find information on the Web, including 59% who do so on a typical day. This places search at the top of the list of most popular online activities among U.S. adults. But it is not alone at the top. Among online adults, 92% use email, with 61% using it on an average day."
...But me and all my (hipster|geeky|20-something) friends only communicate using a combination of Facebook, Twitter, and SMS! If it's not relevant within my inner circle of friends, then 'anyone who's anyone' doesn't care about it!
i suggest that companies communicate with their users where their users are. which sounds like a useless aphorism, but i think it is actually useful to think about.
how many sites have added authentication based on your facebook/twitter/etc. account instead of your email address/password combo? it's happening.
Overuse of automated out-of-office respondes does far more damage to the medium.