Mid-way though 2016 Google gmail and Microsoft Outlook changed they way emails come into their system and your account. Yahoo and AOL (does anyone still use AOL?) are unaffected. However, many company emails use Outlook or gmail as the email server so these may be affected too. Microsoft 365 is a good example.
We use a contact management email sender called Infusionsoft to manage your "welcome to the class" and other related emails. To speed these to you they are automated. In the past we have asked that you white-list swampschool.org as a "safe sender." This is still recommended however, you will need to add one more "safe" email address if you are using gmail or Outlook. Please white-list
2. Allowed IP address: 126.96.36.199
These are both used to send out our automated emails. Most of the emails will appear as:
"firstname.lastname@example.org on behalf of Swamp School" (or similar i.e. swamp news, swamp support, etc.)
Let us know if we can help. Microsoft 365 is widely used by many companies (including us) and the email configurations can be a bit tricky. It is likely that your IT department may need to help you with this.