Minhagim of ellul-signing off emails
לכבוד מרן שליט׳א
Does the minhag of signing letters off with כתיבה וחתימה טובה during the month of ellul apply to emails as well?
Presumably it would, as after all this is the modern form of letter sending, and there is no reson to believe it is only standard mail.
However it would depend on the nature of the email. When one is writing a formal email similar to a letter it would apply. Small communications more like texting, are more like a quick phone call or conversation to which this minhag does not apply.