We had some DNS issues and since that time we are not receiving the “Task Reminder” email notifications that came from HubSpot noreply@notifications.hubspot.com.
I tried to toggle the notifications off and on as suggested here but there has been no change: Solved: HubSpot Community - We are not receiving Task Notifications or reminders - HubSpot Community
Hi @HScholten and welcome, we are delighted to have you here! 
Thanks for asking the HubSpot Community!
Also, well done to do some research before posting, it’s great to see! 
Can you please follow the steps indicated in the article that @karstenkoehler shared on this post “Email Notifications for Tasks not coming through to email.” and let us know if that did the trick?
Also, I’d love to ask our Top Experts: Hi @danmoyle, @BukunmiOdetayo and @beeginman do you have other suggestions to share with @HScholten, please?
Have a beautiful day and thanks so much in advance for your help! 
Warmly,
Bérangère
Hi @HScholten ,
There could be several reasons why you are not receiving the “Task Reminder” email notifications from HubSpot. Here are a few troubleshooting steps to consider:
- First ensure your email is properly configured with HubSpot.
- Check Your HubSpot Notification Settings – Ensure that the relevant email notifications are enabled in your HubSpot settings.
- Search Your Email Inbox – Look for HubSpot notifications in your inbox and check your spam or junk folders in case they were mistakenly filtered.
- Release Quarantined Emails – If you’re using Outlook or Office 365, check if HubSpot emails have been quarantined and release them accordingly.
Kindly refer to this article for the detailed instructions- Here