When deleting spam emails I get the message, "Delete selected conversations?" prior to my performing the one and only act from which I derive a sense of power, hitting the delete key.
"Conversations?" Doesn't "conversation" have to be two-way? Doesn't my email provider misuse the word, or is my peevologist complex showing? Were I to respond to a message a conversation would occur, but otherwise, no, IMHO.

It's just easier to code the same warning message whether or not you have replied.

Yes, Gmail calls all email messages, one-sided or not, "conversations". As Bob says, it's easier to code that way.

Well, in all fairness to linguistics, you'd think they could come up with a better word.