"Internal Server Error" is that the error can only be resolved by fixes to the Web server software. It is not a client-side problem meaning that the problem is not with your browser, your computer, or your internet connection. This error can only be resolved by fixes to the Web server software . It is up to the administrators of the Web server site to locate and analyse the logs which should give further information about the error. However, if you are a web visitor and want to rule out whether the problem is on your end: Clear your browser cookies and cache Reload or Refresh the Webpage From Server end: Server permission Server timeout Script timeout Errors in .htaccess files Check the Error Logs ... View more

It is because Google blocks sign-in attempts from apps which do not use modern security standards (mentioned on their support page). You can however, turn on/off this safety feature by going to the link below: Go to this link and select Turn On https://www.google.com/settings/security/lesssecureapps Moreover google block an ip when you try to send a email since a unusual location, so, you can unblock in the next link https://support.google.com/accounts/answer/6009563 and clicked in accounts.google.com/DisplayUnlockCaptcha . ... View more