Emails occasionally returned with an undeliverable message similar to the following message have been flagged as spam by the recipient:

"Your message couldn't be delivered because the recipient's email server (outside Office 365) suspected that your message was spam. To fix this, try to modify your message, or change how you're sending the message, using the guidance in this article: E-mailing Best Practices for Senders. 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 (the text after the "@" symbol in your email address) to their allowed senders list."

Remote server returned message detected as spam -> 550 permanent failure for one or more recipients

Remote server returned message detected as spam -> 554 rejected due to spam URL in content

Microsoft publishes a best Bulk E-mailing Best Practices for Senders that details recommended practices for senders, but most UW-Stout bounce backs for this reason are triggered by links in email signatures. Consider removing hyperlinks from email signatures and resending the message. Hyperlinks, either in the body of the email or in a signature, pointing to non-Stout sites are particularly problematic.

Detailed tips can be found on the Microsoft best practices site, but here are some quick tips

• Remove links from emails and signatures (or remove the "http://" and/or "www" from the beginning so users can copy and paste them)
• Create a single, Stout-hosted web site with information that you would have your readers click on for more information rather than including multiple links, especially to external sites 
• Use descriptive subjects, avoid single word subjects
• Consider using .pdf attachments instead of including numerous images and links in the body of the email (marketing materials, brochures, flyers)

Rejections due to spam are not as a result of any campus policy or change; the evolution of spam filtering and bulk mail practices is worldwide and will continue impact us as both senders and as recipients.