Why are my emails landing in Office 365 spam folders?

Marketer from Email Geeks highlights that just because emails are going to one person's spam folder, doesn't mean it is for everyone (and vice versa).

Email marketer from Mailjet Blog shares that maintaining a good sender reputation is crucial for email deliverability. Factors that influence sender reputation include bounce rates, complaint rates, and engagement rates. They recommend consistently cleaning email lists, segmenting audiences, and sending relevant content to improve engagement and sender reputation, thus reducing the chances of emails landing in Office 365 spam folders.

Email marketer from GMass explains that a strict DMARC policy (e.g., p=reject) can cause emails to be blocked if they fail SPF or DKIM checks. If using third-party sending services, ensure they are properly aligned with your DMARC policy. A misconfigured DMARC policy can inadvertently send legitimate emails to the spam folder in Office 365.

Email marketer from Email Marketing Forum mentions that high bounce rates are a major red flag for spam filters. Sending to outdated or invalid email addresses significantly damages sender reputation. Regular list cleaning and using double opt-in methods can reduce bounce rates and improve deliverability to Office 365 inboxes.

Marketer from Email Geeks says that more data is needed, and not to make assumptions about the cause.

Email marketer from ZeroBounce shares that if your domain or IP is on a blocklist, your emails are likely to land in the spam folder. They recommend checking your domain and IP against common blocklists and taking steps to get removed if you find yourself listed.

Email marketer from Litmus recommends regularly cleaning your email list to remove inactive or invalid addresses. This helps to improve your sender reputation and reduce the likelihood of your emails landing in the spam folder in Office 365.

Email marketer from Sendinblue Blog explains that a poor IP address reputation can cause emails to be filtered as spam. Sharing an IP with spammers (using shared IPs) can negatively impact deliverability. They advise warming up new IPs gradually, monitoring IP reputation using tools like Sender Score, and considering dedicated IPs for larger email volumes to maintain a positive reputation and avoid Office 365 spam filters.

Marketer from Email Geeks shares that the first place to look is at bounce and complaint rates, and any recent changes in those rates or open rates.

Marketer from Email Geeks responds that if the emails never land in the primary inbox in Office 365, then Microsoft likely has a problem with the emails, and possibly other providers as well, but more data is needed to confirm.

Email marketer from Campaign Monitor explains that the design of your email can affect deliverability. Emails that are too image-heavy or lack sufficient text can be flagged as spam. They recommend using a balanced mix of images and text and ensuring that your email is mobile-friendly.

Marketer from Email Geeks advises getting more data from the providers, and suggests signing up sending IP(s) for Microsoft's SNDS and signing up domain(s) to Google's Postmaster Tools.

Email marketer from Reddit shares that Office 365's spam filters are often aggressive. Even legitimate emails can be caught if they lack proper authentication (SPF, DKIM, DMARC) or if the sender's domain is relatively new and lacks a strong reputation. Consistent sending practices and engagement are key.

Email marketer from Neil Patel's Blog explains that certain words and phrases can trigger spam filters. Using overly promotional language, ALL CAPS, excessive exclamation points, or misleading subject lines can increase the likelihood of emails being flagged as spam by Office 365.

Expert from Word to the Wise shares the importance of list hygiene. Regularly cleaning your email list to remove inactive or invalid email addresses is essential for maintaining a good sender reputation and preventing your emails from landing in the spam folder. Sending emails to nonexistent or abandoned email addresses will increase your bounce rate, which can negatively impact your deliverability.

Expert from Spam Resource shares that the presence and correct configuration of email authentication protocols like SPF, DKIM, and DMARC are crucial. These protocols help verify that the emails are actually coming from the domain they claim to be, and a lack of them can raise red flags for Office 365.

Expert from Spam Resource explains that your IP address reputation plays a significant role in whether your emails land in the inbox or the spam folder. If your IP has been used for spamming activities in the past, or if it's a new IP that hasn't built a good reputation yet, Office 365 may flag your emails as spam.

Expert from Word to the Wise explains that sender reputation, based on factors like bounce rates, complaint rates, and engagement, is important. Office 365 will look at how recipients interact with your emails. If a high percentage of recipients mark your emails as spam or if you have a high bounce rate, this damages your sender reputation and increases the likelihood of your emails going to the spam folder.

Documentation from RFC-6376 specifies that the DomainKeys Identified Mail (DKIM) defines a domain-level authentication framework for email. It permits signing of messages by an organization that controls the domain, which is then verified by message recipients. The signature travels with the email, allowing it to be verified at each hop along the mail path.

Documentation from Microsoft Learn explains that emails might end up in the Junk Email folder due to various reasons, including the sender's IP address or domain being on a blocklist, content triggering spam filters, or the recipient marking similar emails as junk in the past. They recommend checking sender reputation, ensuring proper email authentication (SPF, DKIM, DMARC), and providing clear unsubscribe options.

Documentation from Microsoft Learn explains that Sender Policy Framework (SPF) records are essential for email authentication. It verifies that mail servers are authorized to send emails on behalf of your domain. Incorrect or missing SPF records can lead to emails being flagged as spam by Office 365.

Documentation from Microsoft Learn explains that DomainKeys Identified Mail (DKIM) adds a digital signature to outgoing emails. This allows recipient mail servers to verify the email's authenticity and that it hasn't been tampered with during transit. Implementing DKIM enhances email security and helps prevent spoofing, improving deliverability to Office 365 inboxes.

Documentation from RFC-6376 explains that Domain-based Message Authentication, Reporting & Conformance (DMARC) is a technical specification created by a group of major email providers. It helps protect email senders and recipients from spoofing, phishing, and other email-based attacks. DMARC builds on the widely deployed Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) mechanisms, adding a reporting function that allows senders and receivers to improve and monitor protection of the email channel.

Documentation from RFC-4408 specifies that the Sender Policy Framework (SPF) is a simple email-validation system designed to detect email spoofing by providing a mechanism to allow mail exchangers to check that incoming mail from a domain comes from a host authorized by that domain's administrators. The goal is to allow domains to authorize which hosts are allowed to send mail using their domain names, thus preventing spammers from forging the sender addresses.