Why are transactional emails from a WordPress site using Mailgun being rate limited by Outlook and Yahoo?

Email marketer from Reddit shares that shared IP addresses on Mailgun can be affected by other users' sending habits. If another user on the same IP is sending spam or has poor sending practices, it can negatively impact the IP's reputation, leading to rate limiting by providers like Outlook and Yahoo.

Email marketer from Stack Overflow explains that WordPress plugins might be misconfigured or outdated, leading to incorrect headers or sending practices that trigger spam filters. Checks SPF and DKIM records are essential.

Email marketer from EmailGeeks Forum explains that very low email volume (e.g., only a few transactional emails per day) can make it difficult to build a positive IP reputation with shared IPs. Email providers may be more suspicious of low-volume senders, leading to rate limiting.

Email marketer from Mailgun Help Center explains that rate limiting can occur if Mailgun's shared IPs are experiencing issues due to other users' sending practices, affecting overall IP reputation. Mailgun monitors IP reputation and takes steps to remediate issues, but this can sometimes cause temporary deliverability problems.

Email marketer from Quora recommends warming up the sending IP address gradually. Starting with a small volume of emails and gradually increasing it over time can help build a positive reputation with email providers, avoiding immediate rate limiting.

Email marketer from WP Mail SMTP shares that, in their FAQs, common issues are misconfigured plugins and the need to use a proper SMTP service and ensure correct authentication settings to prevent emails from being marked as spam or rate limited.

Email marketer from Email on Acid blog shares that email deliverability issues, including rate limiting, can occur if the sender's domain or IP address has a poor reputation due to spam complaints, low engagement, or sending to invalid email addresses. Monitoring sender reputation and following best practices can improve deliverability.

Email marketer from Email Geeks asks if the IP is dedicated or shared, and whether there are spikes in volume. Explains that the errors suggest unusual volume spikes or poor IP reputation, common during IP warm-up.

Email marketer from WordPress Forums shares that incorrect or missing DNS records (SPF, DKIM, DMARC) can cause email providers to distrust emails sent from your domain, leading to rate limiting or rejection. Ensuring these records are properly configured is crucial for deliverability.

Expert from Spam Resource, Laura Atkins, explains that using shared IPs can lead to deliverability issues if other users on the same IP engage in poor sending practices. This affects the overall IP reputation and can cause rate limiting by email providers.

Expert from Email Geeks explains that the 4.7.650 error code indicates a 4xx deferral, meaning the email will eventually be delivered or rejected. If rejections are not seen, the issue is delayed email sending.

Expert from Word to the Wise explains that even with transactional emails, proper authentication (SPF, DKIM, DMARC) is crucial. If these are not set up correctly for your WordPress site and Mailgun, Outlook and Yahoo may rate limit or block the emails.

Expert from Email Geeks explains that domain reputation is tricky to measure and asks how long the domain has been sending, if there are captchas/limits on emails triggered from the website, and what the original deliverability problems were before Mailgun.

Expert from Email Geeks says that the IP looks shared and has moderate volume with decent reputation. Suggests ensuring authentication aligns with the from domain, checking domain reputation, and examining the message creation pathway in WordPress for potential abuse.

Expert from Email Geeks suggests avoiding a private IP due to low email volume, and recommends focusing on proper email authentication. He advises sending a test email to aboutmy.email to check authentication setup. Also warns about WordPress security and potential subscription bomb attacks.

Expert from Email Geeks suggests that it is a new mailstream and giving the filters a few days to notice may be all that’s needed.

Expert from Email Geeks states that sending directly from WordPress on an OVH VPS results in poor reputation, and Mailgun will be much better. Advises giving things time to settle.

Documentation from Mailgun explains that using a shared IP means your email sending reputation is influenced by other Mailgun customers using the same IP. If their sending practices are poor, it can negatively affect your deliverability. Dedicated IPs offer more control over your reputation.

Documentation from Postmark shares that to improve deliverability with transactional emails, ensure proper authentication (SPF, DKIM, DMARC), monitor bounce rates, and segment your email list to only send to engaged users. Also, avoid sending marketing emails from the same IP address as transactional emails.

Documentation from Microsoft details that Outlook.com uses IP reputation as a factor in filtering email. Sending from IPs with low reputation can result in rate limiting or blocked delivery. Factors contributing to low reputation include spam complaints, high bounce rates, and sending to spam traps.

Documentation from Yahoo indicates that Yahoo Mail uses a variety of methods to determine mail acceptance including sender authentication (SPF, DKIM, DMARC), sender reputation, and user engagement. Senders who don't follow best practices may experience rate limiting or delivery issues.