Now I know where Miss Ayelery spends all her time when she isn’t correcting our grammar over here.
SPOGG: The Society for the Promotion of Good Grammar
Miss Ayelery likely drinks her tea from a SPOGG mug.
John dear, I’m afraid you have “outed” me. As a contributor to SPOGG, I’ve been hesitant to advocate the site or the Society in these fora out of “conflict of interest” concerns. Of course, that doesn’t stop me from advocating unicycling to my SPOGG peers. 
MA
PS: I love my SPOGG mug, and have found it works equally well for tea and for Irish Coffee.
There is no need for a comma when you are not changing the subject of the phrase.
I am almost sure you are supposed to put one before the word and just like you would but.
Miss Ayelery, due in part to the enormous pressure placed on one in her position, may very well have been in her cups and deservedly so at the time she wrote her response. This would be Irish coffee put to its finest use. In this particular case she may have been in her mugs rather than her cups.
Jethro-
This seems to be excellent advice from someone obviously very well versed in this field. Take note of this and ponder its meaning.
Is it possible to die from an overdose?
An overdose of bad grammar? Yes.