I placed a comment on this question, recommending the OP to recommend Gmail to the other party due to its "did you forget to attach the file?" feature. This comment has disappeared for some reason and I don't know why (I think you should be able to see it with over 10k rep). Moreover, there is another comment there now saying essentially the same thing.
Im curious what happened to my comment. Was it removed (and why) or is there some bug deleting comments?
I deleted that comment, along with several followups and a brewing argument over the relative merits of Gmail and other platforms. Thank you for alerting me to the fact that others subsequently started that discussion again; I've now deleted those and left a comment saying so.
Comments are not for discussions and they especially aren't for answers. A quick comment pointing someone in the right direction is generally harmless, but when they spawn long threads and those threads get flagged, or we just come across them in the normal course of using the site, mods tend to delete them. You should think of comments as ephemeral; if you want something to be more durable, find a way to incorporate it into an answer. If you want to have a discussion, please do so -- in a chat room, not in comments on a question or answer.
Adding on to what Monica said, when you go to post a comment on a question you see the following:
The comments which Monica deleted there did not ask for more information nor suggest improvements to the question. Some of them were sort of answers, but the majority were a discussion tangentially related to the question.
There is a lengthy FAQ about comments here. I would encourage you to read the information page on comments, too, specifically:
When shouldn't I comment?
Comments are not recommended for any of the following:
Suggesting corrections that don't fundamentally change the meaning of the post; instead, make or suggest an edit;
Answering a question or providing an alternate solution to an existing answer; instead, post an actual answer (or edit to expand an existing one);
Compliments which do not add new information ("+1, great answer!"); instead, up-vote it and pay it forward;
Criticisms which do not add anything constructive ("-1, see previous comments you scallywag!"); instead, down-vote (and provide or up-vote a better answer if appropriate);
Secondary discussion or debating a controversial point; please use chat instead;
Discussion of community behavior or site policies; please use meta instead.
Hopefully this helps!
