It’s definitely frustrating when you find out that some of your outgoing messages are being sent to your recipient's spam folder.
The most likely reason for this problem has to do with email reputation. Thundermail's IP addresses were recently created (since we're a brand new service), so we might not get perfectly through to all providers quite yet.
How Can I Help?
When this happens, you can ask your recipients to mark your messages as "Not Spam." In Thunderbird, they can do that by highlighting the message and pressing Shift + J.
This helps train their email provider to trust your messages and our domains.
You can also provide more information through a support request in order to help our research! Click here to open a new ticket and please include the following:
- What providers are flagging your messages as spam?
- Are these "test" emails? Or full emails with content?
- Are you using a custom domain, @thundermail.com, or @tb.pro as the sending domain?
- If using aliases, could you tell us which ones are getting flagged?
Thanks so much for your assistance! We are actively working to improve this as quickly as possible.