High spam complaint rates during email warm-up are a complex issue stemming from various factors. Initial low sending volumes can skew the spam rate calculations, making even a few complaints appear significant. Poor list quality, irrelevant or poorly targeted content, and a lack of recognition from recipients contribute to increased spam reports. Inconsistent sending volumes, the use of spam trigger words, and failure to properly authenticate emails can also raise red flags with email providers. Actively engaging with feedback loops, focusing on relevant content, and only sending to engaged users is crucial for establishing a positive sending reputation during the warm-up phase. Always check the IP reputation before warming up the IP. Using double-opt ensures recipients want to receive emails.
14 marketer opinions
High spam complaint rates during email warm-up can be attributed to several factors. Low initial sending volumes can skew complaint rates. Poor list quality, irrelevant content, and lack of recipient familiarity contribute to users marking emails as spam. Inconsistent sending patterns, the use of spam trigger words, and lack of proper email authentication also raise red flags with email providers. Engagement (or lack thereof), double opt-in, and Gmail specific spam algorithms should also be considered.
Marketer view
Email marketer from Email Marketing Forum shares that using spam trigger words in your subject lines during warm-up can significantly increase spam complaints. Avoiding these words and focusing on clear, concise messaging is crucial for maintaining a positive sending reputation.
25 May 2022 - Email Marketing Forum
Marketer view
Marketer from Email Geeks explains that Counting today’s marks against today’s mail is just to get an idea of the scale of the issue. If the scale is very small, a high rate isn’t really a cause for concern.
26 Jan 2024 - Email Geeks
3 expert opinions
High spam complaint rates during email warm-up can be mitigated by focusing on establishing trust and monitoring recipient reactions. Setting up proper email authentication (SPF, DKIM, DMARC) before starting the warm-up process is essential. Additionally, monitoring spam complaints through feedback loops with major ISPs provides valuable data for adjusting sending practices. Sending exclusively to engaged users during warm-up minimizes complaints and builds a positive sender reputation.
Expert view
Expert from Spam Resource explains that setting up proper authentication (SPF, DKIM, DMARC) before beginning your warm-up process is crucial. This helps establish trust with mailbox providers from the start, reducing the likelihood of being marked as spam.
2 Jan 2025 - Spam Resource
Expert view
Expert from Spam Resource explains the importance of only sending to engaged users during the warm-up phase. Targeting recipients who have recently interacted with your emails or website helps minimize spam complaints and build a positive sender reputation.
9 Dec 2023 - Spam Resource
5 technical articles
High spam complaint rates during email warm-up have a significant impact on sender reputation and deliverability. Spam reports directly impact sender reputation and trigger filters (Google). Feedback loops provide data on complaints to adjust sending (Microsoft). Proper sender authentication is crucial (RFC). Pre-warming IP reputation checks are recommended (Spamhaus) to avoid blocklists. Sending relevant email to only those who want it and awareness of sending limits are important factors (AWS).
Technical article
Documentation from AWS shares that you should only send email that your recipients want to receive. Only send as much email as your recipients want to receive and be aware of your sending limits when warming up.
12 Jun 2022 - AWS
Technical article
Documentation from Spamhaus explains that you should check your IP reputation prior to warming up your ip to ensure your IP is not on any blocklists.
11 Nov 2024 - Spamhaus
Are IP warming services effective for improving email deliverability?
Do I need an IP warm-up when moving to a new ESP with shared IPs?
How do I contact the Yahoo postmaster for deliverability issues during IP warm-up?
How can I improve email deliverability for a client with a poor sender reputation and questionable email acquisition practices?
How do I contact the AT&T postmaster and what domains are associated with their email filtering?
Can Proofpoint implementation and MX record changes during IP warming affect email deliverability?
© 2025 Suped Pty Ltd