We have increased the usage limits.
New rate limiters are:

• Gmail users:
  • 250 emails per hour
  • 300 emails per day
• Gapps users:
  • 1600 emails per hour
  • 2000 emails per day

go to the top right hand corner of your Chrome browser and click on the little
grid to open the settings menu. Then mouse to Tools then Extensions. Look for mxHero and either disable or remove.

If this doesn't work, try using the following URL (xyz.com being your domain).This will remove your email flow from our servers.
https://services.mxhero.com/gappsuscriptor/gapps/uninstall?domain=xyz.com

We've recently changed the way our platform interacts with Google. This issue has been solved, please make sure you've installed the latest version on your browser:
Mail2Cloud for Chrome | Revolutionizing Email 2.10.5

Thanks for subscribing,

MxHero Team.

You could use short codes: 
https://mxhero.zendesk.com/hc/en-us/articles/200910679-Shortcodes-Using-Built-In-Features-from-Anywhere

The issue is fixed. Please update the Chrome Extension through the Chrome Web Store or the Chrome Extensions Manager in your browser!
The issue in fact occurred due to changes in the Gmail application  code, the version must be 2.9.0

Hi, 
We've detected some internal changes into the Gmail interface application code which requires a few adjustments into our Chrome Extension as well.
We are working to make these adjustments and have the mxHero button available again asap.

Hello, 
sending emails to yourself will not work as Google will not process them and they will remain in your inbox. You should try sending the test email to a different email address than the one you're sending it from.

Hi Shawn, unfortunately the log on the console is not related to the issue you describe, is only a warning related to the fact that the request is done to our server in that case over http instead of https. This is something that we are changing in the next week.
Related to the other issue, would you willing to do a screenshare to try to debug the problem? If you can please send an email to mmarmol@mxhero.com to coordinate.

Regards, 

This week we have been working on some improvements on the processing side. So just to let you know that we realize that this last couple weeks emails could stuck on draft for up to 1 minute before been send. Also if the email was accessed while doing this the email may have been prevented to leave the draft at all and even not been sent.
Now after the changes we are seeing a stable time around 2 to 8 seconds processing. While that emails will stay in draft.
Yo understand if an email was actually sent by mxhero at all, you can check the Sent folder and if it is there, them the email was successfully delivered.
Also just to let everyone know, emails where the sender and the recipient belong to the same inbox are not actually processed by mxHero. So you won't find them on the inbox after sending them, but you should see it on the Sent folder.

Please let us know if anyone is currently today experiencing issue with the extension, so we may look at the particular case.

Thanks again for supporting our Beta extension, and we really sorry to hear the problems that this is giving you on your email use.

Regards,

Hi, we have been working on mxHero processing time and redundancy of the service, and now it should be almost instant. Let us know if you see the problem again.