Question about arXiv replacement restriction and contacting moderators Background: I submitted an article (denoted by A) on arXiv half a year ago and have replaced it several times later. Due to frequent replacements, one of my further replacements is removed, and I'm restricted to replace the article at most once per calendar month.
Question 1: Several days ago I submitted another one (denoted by B) onto arXiv and succeeded. Now I have some new ideas added to B and want to replace it. I wonder if the restriction is only on article A, or both article A and B? In other words, can I update B within this calendar month?
Question 2: I sent several e-mails to arXiv moderation (help@arxiv.org), but all of them are rejected, saying &quot;Your message was missing suitable identifying information&quot; etc. Nevertheless, I've included all relevant informations following the instruction, also &quot;Dear arXiv,&quot; is added in preface. Can someone show me how can I modify my message to deliver my email? Are arXiv moderators really that hard to contact with?
Any suggestions is appreciated.

I retried sending emails to arXiv moderation but all my attemptions failed. Therefore I update the article B directly, as a result, the replacement succeeded. Thus, question 1 is solved.
Still I have no idea about the second question, since all of my 2 mailboxes (academic/private) failed to deliver the email.
My best suggestion is to stop making replacements so frequently and wait until you think you have a ready pre-print, before you submit to arXiv. The arXiv is, after all, an archive for pre-prints and articles, and not a server for uploading new drafts on a daily basis.
I honestly fail to see the need to make updates to an arXiv entry, more frequently than monthly, on a regular basis. My own work-flow - for an article with many replacements - is roughly the following:

Pre-print ready, upload to the arXiv.
(+2 weeks) Get comments on the arXiv pre-print from colleagues, incorporate then, make a replacement, submit to journal.
(+1-2 months) Get comments from journal referee, incorporate, make a replacement, resubmit to journal.
(+1 month) Possibly final comments, final proofs, replacement to final version.

I assume that you upload your work to arXiv to allow other people to read it. Consider that it only serves to confuse your readers, if you make too frequent updates. I would never expect that a pre-print I have once read, will change drastically on a weekly basis after I read it the first time.
Perhaps you should re-consider your format? If you want to be able to write down thoughts quickly, and release them to the world, perhaps a blog would be more suitable?