Outside emails being considered SPAM

Hello,

I was advised by a former member that someone from Health Canada had tried emailing the president-9303@toastmasters.org email address for Nepean Wingtalkers Toastmasters and they got back an undeliverable message.

I tested it from my CBSA (government) email address and haven't seen it show up in my inbox, but I haven't received an undeliverable message yet. Please see below for the message that they received. Is there something I need to do to fix this? Please help me understand what happened.

This is the message that they received: Your message to  This email address is being protected from spambots. You need JavaScript enabled to view it.  couldn't be delivered. toastmasters.org  suspects your message is spam and rejected it.Carol.GonsalvesOffice 365 toastmasters.org Sender Action Required       Messages suspected as spam How to Fix ItTry to modify your message, or change how you're sending the message, using the guidance in this article:  Bulk E-mailing Best Practices for Senders Using Forefront Online Protection for Exchange . Then resend your message.If you continue to experience the problem, contact the recipient by some other means (by phone, for example) and ask them to ask their email admin to add your email address, or your domain name, to their allowed senders list. 
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More Info for Email AdminsStatus code: 550 5.7.350

When Office 365 tried to send the message to the recipient (outside Office 365), the recipient's email server (or email filtering service) suspected the sender's message is spam.

If the sender can't fix the problem by modifying their message, contact the recipient's email admin and ask them to add your domain name, or the sender's email address, to their list of allowed senders.

Although the sender may be able to alter the message contents to fix this issue, it's likely that only the recipient's email admin can fix this problem. Unfortunately, Office 365 Support is unlikely to be able to help fix these kinds of externally reported errors.Original Message DetailsCreated Date:12/19/2022 8:39:14 PMSender Address: This email address is being protected from spambots. You need JavaScript enabled to view it. Recipient Address: This email address is being protected from spambots. You need JavaScript enabled to view it. Subject:information about TM Nepean
Error DetailsReported error:550 5.7.350 Remote server returned message detected as spam -> 550 permanent failure for one or more recipients ( 5.4.1 Recipient address rejected: Access denied. AS(201806281) [MW2NAM12FT056.eop...)DSN generated by: YT3PR01MB10704.CANPRD01.PROD.OUTLOOK.COM  

The domain for your FreeToastHost email addresses is toastmastersclubs.org, not toastmasters.org