If you get an error message when trying to send out offers, meeting invites or newsletters/emails, the issue is most likely that there is no connection between webCRM and your email provider anymore.
In most cases this can be solved by checking your external credential settings in webCRM.
To find these settings you can click on your initials in the top right and select "External credentials settings":
Here you choose your email provider. You can either choose Google/Gmail or Exchange/Office 365, and the Sign out.
Then you sign in again, approve and make sure at least For Email is activated. Click Save, and you can now send emails again.