Having emails stuck in the inbox is a fairly common problem in Gmail: the user wrote an email, clicked to send it, but stays in the inbox folder and Gmail doesn't send the email, no matter what. This article details the possible causes and solutions and applies to Gmail or Google account.
There may be many reasons why Gmail would not send an email. To reduce the cause of the emails stuck in the inbox, the user must first verify if he receives an error message while performing a Send / Receive operation.
If Gmail user receives an error message when trying to send the email
Most likely, there is a communication problem between Gmail and the users' outgoing mail server, so the email is stuck in the inbox because Gmail can’t connect to the users' mail server to send it.
Check with the user's Internet service provider to ensure that the user does not block the port number that the user is using for the outgoing mail server (some providers block port 25 or other ports that a server can use outgoing mail / SMTP);
Check with the provider of the user's email address and make sure the mail server settings are up to date. Occasionally, mail server providers change port numbers or authentication methods, so even if the users' Gmail account used to send emails without any problems, it may no longer work because the configuration was modified of the server. outgoing mail;
Check with the provider of the users' email address and make sure that the user does not exceed the hourly/daily shipping rate (or other shipping limits imposed by the users' email provider);
If the user has a slow Internet connection, make sure that the emails in the users' inbox do not include very large attachments (10-20 Mb or more). The server connection may time out before Gmail sends a large email;
If the above solutions do not work, use Google and look for the exact error code the user received when trying to send a Gmail email: it will probably lead the user to an accurate solution. The user should also consult this list of the most common error messages to send and receive and their solutions.
If Gmail user did not receive any error message when trying to send the email
The problem is likely to be related to the local Gmail settings of the users. If Gmail does not send only some emails in the inbox, make sure that the user does not have the habit of previewing / opening / clicking the emails in the inbox: the emails in the inbox User input should not be read (marked with bold and italic) otherwise, Gmail will. Do not send the email and it will get stuck in the user's inbox folder. Verify user emails:
If the email is bold and italic, it is ready to be sent;
if the email is marked in bold, it was read;
If the email is not marked with bold and italic, then the email was read and edited. As in the following screenshot, Gmail will only send the first email (with the subject "Unread email") while the other emails will remain in the inbox folder:
Gmail Not Sending Emails
If Gmail does not send any of the users emails in the inbox and they are not marked as read (as indicated above) try one of the following solutions:
Make sure that Gmail is not set to offline mode. The user can check if Gmail is disconnected from the Send / Receive ribbon button (toolbar):
Make sure that the user does not have an antivirus that is too enthusiastic to scan emails in the inbox of users and prevent them from being sent. Make a simple test and disable the antivirus protection of users, restart Gmail, and try to send emails from the inbox once again. If they are sent, configure antivirus users and prevent them from scanning emails in the inbox.