New ESP activated, mail now lands in spam at scale
New IPs and domains have no reputation. Sending 50,000 mails immediately from a cold IP is treated as suspicious by Gmail, Outlook and large ISPs. Warmup is gradually ramping volume over two to four weeks, starting with your most engaged recipients.
Try this first
- 1Start with 50 to 100 mails per day to your most engaged segment (opened or clicked in the past 90 days). Roughly double per day toward target volume.
- 2Send transactional first (welcome, confirmation) and only add marketing after 10 days. Transactional has higher engagement.
- 3Track bounces, complaints, unsubscribes daily. If complaints spike, slow down.
- 4Enable Postmaster Tools (Google) and SNDS (Microsoft) on day one so you see reputation build.
- 5Plan 14 to 28 days minimum for warmup. ESPs like Postmark or SendGrid have warmup schedules and automatic throttling.
When to bring us in
If you migrate 100k+ contacts at once with no warmup window, a dual-send (taper old IP while ramping new) is more realistic than a hard cutover.
See also
- Our emails land in spam for some recipientsAlmost always an SPF, DKIM, or DMARC setting that is wrong or missing, or a sender name that mimics a well-known brand.
- Someone reports receiving phishing emails "from us"Read: spoofing. Someone is abusing your sender name, not necessarily your actual mailbox.
- An email bounces (NDR): delivery failedThe NDR text usually states the exact reason. Reading it is step one.
None of the above fits?
Describe your situation below. We pass your input plus the steps you already saw to our AI and return tailored next-step advice. If it's too risky to DIY, we'll say so.
Or skip the DIY entirely
Our Managed IT clients do not look these things up. One point of contact, a fixed monthly price, resolved within working hours.