The first time I tried to send archived files to/from a Gmail email account was 1 month ago and I noticed that you cannot send this kind of files. I tried multiple times and failed always.If I send an email to a Gmail account, I get a reply with the text message:This is an automatically generated Delivery Status Notification.Delivery to the following recipients failed.anemailaddress@gmail.comViewing the email source, I found out this:Final-Recipient: rfc822;anemailaddress@gmail.com Action: failed  Status: 5.5.0 Diagnostic-Code: smtp;552-5.7.0 This message was blocked  because its content presents a potential 552-5.7.0 security issue.  Please visit 552-5.7.0http://support.google.com/mail/bin/answer.py?answer=6590 to review our  552 5.7.0 message content and attachment content guidelines.  m3si23238476wjw.33 - gsmtpIs there a way to circumvent this? The archived files I tried were zip, rar, no password, with password, encrypted. None of them worked. The archive contained a Kicad project.
Cannot attach/send archived files from/to Gmail email address
gmail;email;attachment;gmail attachments
You should try with 7zip, which use 7z file format.The mail server in my school blocked .exe and .vbs files when they were zipped but not when they were 7zipped.So in the case of some files are not allowed by Gmail to be send or receive, it might pass the checking.http://www.7-zip.org/