Fix: Oops… a server error occurred and your email was not sent (#707)

The error “Oops… a server error occurred and your email was not sent. (#707)” usually occurs when the Gmail client is unable to establish a working connection with its servers. You are actually sending the mail to the Gmail servers which are in turn storing it into the account of the recipient you targeted in the email. When there is a hindrance to this communication, you get the error message.

This issue particularly arises in Firefox browser and there are numerous workarounds which work for this issue as well. The most common workaround is disabling the Avast Email Signature. Other workarounds also include composing a new email, clearing browser cache, reinstalling the browser etc. We will go through all of them one by one with the most significant fixes starting from the top.

Solution 1: Disabling Avast Email Signature

Like all other antivirus applications, Avast scans your email for all potential threats (detecting links for phishing, scams etc.) and removes them accordingly so your computer can be safe. This includes identifying suspicious keywords and command line sentences present in your or other emails targeted towards. Along with providing this safety measure, the application also includes an Avast Logo at the end of each email to show that your email was scanned and declared safe by the software.

There were numerous reports from many users who running Gmail on Firefox that this was the cause of the issue. We will first try to disable the Avast email signature from the application and check if this solves the problem. If it doesn’t, you should go ahead and temporarily disable the antivirus. If even this doesn’t work, consider uninstalling it and see if this makes any difference. We are putting an emphasis on Avast as in more than 80% of the cases, this was the culprit.

  1. Open your Avast application by clicking on the icon present at your taskbar.
  2. Once in the application, click on the ‘gears’ icon present at the top-right side of the window to open the Settings.
  3. Once in Settings, click on ‘General’ tab in the left navigation pane. Now uncheck the option which says “Enable Avast email signature”. Press OK to save changes and exit.

  1. Restart your computer and see if this fixes the problem.

If this doesn’t do any good, you can disable the Mail Shield completely. To do this, click on “Active Protection” using the navigation tab on the left and toggle the option of “Mail Shield” once to turn it off. Press OK to save changes and exit.

Now check if the problem is solved. Also, restart your computer after making the changes so they can be implemented. You can also try temporarily disabling Avast Antivirus and see if this makes any difference.

Solution 2: Composing a New Message

Before we proceed in following other various workarounds, you should try copying the same text you intended to send and send it using a newly composed message. There are many instances that Gmail cannot configure itself properly and access its servers. In such a case, try checking your internet connection. If you are using a proxy server, try connecting to the internet with such restrictions. Furthermore, copy the entire text (present in the mail you are trying to send), compose a new mail, paste the text, and try sending it to the recipient again.

Solution 3: Clearing Browser Cache and Cookies

If the problem only lies with your browser (with the website opening in other devices), we can try clearing your browser data. Your browser may contain fault files which may be causing the problem. When we clear the browser data, everything gets reset and the browser behaves like you are visiting the website for the first time.

  1. Open Firefox, click on the ‘menu icon’ present at the top-right side of the screen and select ‘options’.

  1. Select the tab ‘Privacy and Security’ using the left navigation pane and click on “Clear your recent history”.

  1. Select the time range as “Everything”, check each option and click “Clear Now”.

Note: All your cookies, cache, saved websites, and browsing data will be erased. Make sure to backup all your important information before carrying out this step.

  1. After clearing, restart your computer and check if the problem at hand got solved.

Solution 4: Reinstalling Firefox

If all the above methods fail, you should consider reinstalling Firefox. There are numerous cases where this browser fails configure itself properly which in return causes various malfunctions and error messages. Backup all your data present on Firefox before you proceed with this solution.

  1. Press Windows + R, type “appwiz.cpl” in the dialogue box and press Enter.
  2. All the programs installed on your computer will be listed here. Right-click on the application and click on “Uninstall”.

  1. After uninstalling the browser, head over to Firefox’s official website and install the latest client available.

  1. Now check if you can correctly send the mail without any problems.

Note: Try opening your Gmail account in a private window and see how it goes there.


If you have tried all the above solutions with no luck, try opening your account from another PC connected to the same network as you and see if the error is still present there. Most of the times there are various networks in which you cannot properly send the mail due to overprotective firewalls or some other protection software. Furthermore, you should also check the status of Gmail servers. It is possible that there is an outrage in your area. Google it and you can select any of the websites to check the status


Kevin Arrows

Kevin Arrows is a highly experienced and knowledgeable technology specialist with over a decade of industry experience. He holds a Microsoft Certified Technology Specialist (MCTS) certification and has a deep passion for staying up-to-date on the latest tech developments. Kevin has written extensively on a wide range of tech-related topics, showcasing his expertise and knowledge in areas such as software development, cybersecurity, and cloud computing. His contributions to the tech field have been widely recognized and respected by his peers, and he is highly regarded for his ability to explain complex technical concepts in a clear and concise manner.