Why are my emails going to junk folder during Microsoft IP warmup even with good metrics?

Email marketer from GlockApps Blog explains that even with proper IP warm-up, sending to a list with poor hygiene can lead to emails landing in spam. A high number of inactive or invalid email addresses on your list can trigger spam filters, regardless of your IP reputation.

Email marketer from Talos Intelligence highlights that the sending domain's reputation is crucial, regardless of the IP warmup process. Even with a properly warmed-up IP, a domain with a poor reputation can lead to emails being filtered as spam. This includes domain age, historical spam complaints, and association with malicious activities.

Email marketer from StackOverflow user 'EmailGuru' responds that Microsoft may implement aggressive throttling to new IPs. Even if everything looks fine, the volume may be artificially limited so that you are not sending enough volume to establish a reliable reputation with the provider.

Email marketer from Litmus Blog explains that missing or incorrectly configured email authentication records (SPF, DKIM, DMARC) can cause deliverability problems, especially during IP warm-up. ISPs use these records to verify the sender's identity, and their absence can result in emails being flagged as spam.

Email marketer from Gmass explains that you must avoid spam traps. Sending email to spam traps is one of the biggest red flags for mailbox providers. Hitting them will damage your deliverability right away.

Email marketer from Email Geeks shares that with new accounts during IP warm-up, emails are hitting the junk folder even with no bounces and great rates, starting around day 3-4. Microsoft support reports no issues with the IP, and header analysis shows SCL = 0 with no spam treatment applied.

Email marketer from SendGrid Blog shares that, even with a warmed-up IP, emails can still go to spam due to content triggers. They emphasize that spam filters analyze email content, and certain keywords or phrases, combined with poor formatting or excessive use of images, can negatively impact deliverability, especially during the initial stages of sending.

Email marketer from Mailjet Blog explains that during IP warm-up, even with good initial metrics, emails can land in spam due to the lack of established sender reputation. Microsoft and other ISPs look at the volume, consistency, and user engagement over time to determine trustworthiness.

Email marketer from Email on Acid Blog shares the importance of actively monitoring deliverability during IP warm-up, including using seed lists, checking spam traps, and analyzing bounce and complaint rates. Even with seemingly good metrics, subtle deliverability issues can be missed without proper monitoring.

Email marketer from Reddit user /u/EmailNoob shares that inconsistent sending volumes during IP warm-up can confuse ISPs and lead to deliverability issues. Rapidly increasing sending volume or significant daily fluctuations might trigger spam filters even if overall metrics seem positive.

Expert from Word to the Wise explains that Microsoft's filtering is complex and takes into account a wide range of signals beyond just IP reputation, which can cause emails to land in junk even with good sending metrics. They emphasize that content, engagement, and overall sender behavior play a significant role in placement.

Expert from Spam Resource shares that Microsoft places significant weight on engagement metrics, especially during IP warm-up. Low open rates, click-through rates, and high deletion rates can signal that the email is unwanted, leading to junk folder placement despite good IP reputation.

Expert from Email Geeks states that the Microsoft IP reputation colors are not related to source IP address, and are based on content filters.

Documentation from RFC Editor highlights the importance of having a proper reverse DNS record (PTR record) configured for your sending IP address. A missing or incorrect PTR record can raise red flags with some ISPs, especially during IP warm-up, and increase the likelihood of emails being filtered as spam.

Documentation from Microsoft Support explains that their email filtering systems consider various factors beyond IP reputation, especially during new IP warm-up. These factors include content, sender information, recipient engagement, and infrastructure configuration. Even with good initial metrics, the filtering logic might initially place emails in junk folders until a sufficient reputation is built across these areas.

Documentation from SparkPost explains that in the end ISPs primarily filter based on engagement. Opens, clicks and other engagement actions show your users want your email and this will have positive impact on your deliverability.

Documentation from Google Postmaster Tools explains that spam complaints, even in small numbers, can significantly impact deliverability during IP warm-up. ISPs closely monitor feedback loops and high complaint rates can quickly lead to emails being filtered as spam, overriding positive engagement signals.