Email Swirl means in slang: This is used to identify an email thread which becomes difficult, interminable and frustrating. The defining characteristic of any swirl is that the original question was bogus and the inquiry resulted in the need for the individual to use telephony as a means to solve the problem.
(in Slang Dictionary, added by Eva Gomez)

What else does Email Swirl mean?

This is used to identify an email thread which becomes difficult, interminable and frustrating. The defining characteristic of any swirl is that the original question gets buried in erroneous stuff, causing the inquiryor to use telephony as a means to solve the problem.
(in Slang Dictionary, added by Antonio Allison)