Preventing Microsoft 365 from blocking outbound business development emails requires a multi-faceted approach focused on authentication, sender reputation, and recipient engagement. It is vital to understand that Microsoft prioritizes its users' experience and filters emails that are deemed unwanted or spam. Strong authentication using SPF, DKIM, and DMARC is crucial. Building and maintaining a positive sender reputation involves warming up IP addresses, sending relevant and personalized content, segmenting email lists, cleaning inactive addresses, and obtaining explicit opt-in. Continuous monitoring of sender reputation, bounce rates, spam complaints, and adherence to sending limits is essential. Additionally, the email content must provide value and respect recipient preferences, ensuring easy unsubscribe options and prompt removal of unsubscribed users. Cold emailing without consent is generally discouraged and can lead to blocking.
7 marketer opinions
To prevent Microsoft 365 from blocking outbound business development emails, several strategies should be implemented. These include warming up IP addresses, segmenting email lists, personalizing email content, cleaning email lists of inactive addresses, and employing double opt-in processes. Maintaining a dedicated IP, monitoring sender reputation, using consistent sending volumes, respecting unsubscribe requests, and ensuring emails provide value are also crucial. Additionally, setting up proper email authentication (SPF, DKIM, DMARC) and regularly testing email deliverability are recommended.
Marketer view
Email marketer from EmailonAcid shares that list segmentation is an effective method to improve deliverability. You can send emails to the right people, at the right time. Another factor is personalizing emails as it has a better chance of not being marked as spam.
3 Nov 2024 - EmailonAcid
Marketer view
Email marketer from Woodpecker.co explains that you need to ensure you are using a dedicated IP address for sending your email, this will help protect your reputation. Create a separate domain used just for email campaigns. Avoid using URL shorteners as they are commonly used by spammers.
21 Feb 2025 - Woodpecker.co
4 expert opinions
To prevent Microsoft 365 from blocking outbound business development emails, understanding the perspective of mailbox providers like Microsoft and Gmail is crucial. Microsoft blocks senders for violating their acceptable use policy and deeming emails as spam based on outbound filters. Building and maintaining a good sender reputation through managing IP and domain reputation, improving engagement metrics, and segmenting email lists is important. Proper email authentication with SPF, DKIM, and DMARC is essential, alongside ensuring explicit authorization to send emails by capturing opt-in correctly and only sending desired content. Avoid practices considered spam, such as cold emailing without consent, as most ESPs and deliverability consultants also advise against it.
Expert view
Expert from Word to the Wise explains that you need to focus on building and maintaining a good sender reputation, which includes managing your IP address reputation, domain reputation, and engagement metrics. Ensure your sending infrastructure is properly configured with SPF, DKIM, and DMARC. Also, segment your list to send relevant emails to engaged subscribers, and avoid sending to inactive or unengaged recipients.
21 Mar 2025 - Word to the Wise
Expert view
Expert from Email Geeks shares that it doesn't matter if we think cold leads are spam; it's what the mailbox provider thinks. This is why Gmail puts them in the spam folder so often. In this case, there was enough unwanted activity to cause Microsoft to shut it off on the outbound side as they felt it was spam.
7 Nov 2024 - Email Geeks
5 technical articles
To prevent Microsoft 365 from blocking outbound business development emails, a strong emphasis is placed on proper email authentication using SPF, DKIM, and DMARC records. These records authorize sending mail servers, verify email authenticity, and instruct receiving servers on how to handle emails that fail authentication checks. Maintaining a good sender reputation by avoiding unsolicited emails, providing easy unsubscribe options, and monitoring for suspicious activity is crucial. Following sending limits, using TLS connections, tracking sender reputation via Google Postmaster Tools, and checking for domain/IP blocklisting are also recommended. A gradual approach to DMARC policy implementation, starting with monitoring and progressing to stricter enforcement, is advised.
Technical article
Documentation from DMARC.org shares that a DMARC policy tells receiving mail servers what to do with emails that fail SPF and DKIM checks. They suggest starting with a policy of 'p=none' to monitor email flows and gradually move to stricter policies like 'p=quarantine' or 'p=reject' as you gain confidence in your email authentication setup. Regularly review DMARC reports to identify and address any authentication issues.
23 Oct 2024 - DMARC.org
Technical article
Documentation from Google Workspace Admin shares that you need to authenticate your email. Make sure you are setting up SPF, DKIM and DMARC records. Use a TLS connection to ensure emails are secured during transfer. Keep your sending rate within limits. Monitor your sender reputation using Google Postmaster Tools. Check if your domain or IP is on any blocklists.
11 May 2024 - Google Workspace Admin
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