Sending full volume on day one looks exactly like a spammer
A migration rarely fails because of the platform. It fails because of poor scheduling and sending behavior.
Placement dropped the week you switched
New IPs with no history, full volume from day one.
Fine at Gmail, throttled at Microsoft
Providers warm up at different speeds.
Bounces spiked on the first full send
Your suppression list didn’t come with you.
Both platforms are still sending
Two sources, one domain, inconsistent signals.
You migrated to fix a problem, and it followed
Domain reputation moved with the domain.
Weeks in, and it still hasn’t recovered
No baseline was measured, so nobody can say by how much.
Any of these will cost you deliverability and delivery quality
Each signal tells providers the same thing: this sender arrived from nowhere and behaves unpredictably. Several are usually true at once, and the damage typically happens in the first two weeks. The easiest problems to prevent, and the most expensive to undo.
01
Full volume on day one
The fastest way to burn a new IP: providers read a sudden ramp from an unknown source as snowshoe spam.
02
Warm-up compressed into a week
Most senders need 4 to 8 weeks end-to-end, ramping 25–35% per send. Rushing it sets a ceiling you then spend months climbing back from.
03
Suppression lists left behind
Unsubscribes, hard bounces, and complainers rarely export cleanly across platforms, so they get mailed again — the fastest route to a spike in complaints.
04
Authentication not migrated cleanly
Every platform signs with its own DKIM keys, and an SPF record that still includes the old ESP can exceed the lookup limit.
05
Dedicated IP at too low a volume
Below roughly 100K sends a month, the signal is too thin, and the IP goes cold between campaigns.
06
Two platforms sending at once
Same audience, same domain, unaligned authentication — duplicate sends and contradictory signals.
07
New tracking or link domain
Tracking domains carry their own reputation — a brand-new one is unvouched for on every message.
08
Migrating to escape a problem
Domain reputation follows the domain. You arrive with the same damage, plus a cold-start problem.
You get one first impression with a new IP
The plan decides whether the first two weeks build or erode your reputation — and by the time the numbers show a problem, the ramp is already compromised. A MailSoar expert sizes the warm-up to your volume and tells you what has to be in place before the first send.
How MailSoar makes migrations easy
One framework, four solutions. Most clients start with Find (baseline and plan) and Fix (execute the cutover) — then Run holds placement and Grow turns it into revenue.
Find
Pinpoint exactly what’s breaking your deliverability — before spending a euro on fixes.
Fix
Roll out the technical and content fixes — DNS, warmup, infrastructure — that get your emails back in the inbox.
Grow
Turn stable inbox placement into real growth, with engagement and revenue tracked send by send.
Run
Keep a senior expert watching your reputation, so issues get caught and fixed before they cost you inbox placement.
Turn a clean migration into a platform for growth
Talk to a MailSoar expert to uncover your deliverability issues and get a clear diagnosis of what’s causing them and how to fix them quickly.
Brands that switched ESP without losing the inbox
What MailSoar experts did to boost their deliverability, with clear results.
Is your situation slightly different?
A migration often overlaps with these closely related problems. Start where it fits best:
Switching ESP:
FAQ
Migrate without paying for it in the inbox
Whether the move is next month or three weeks away, our consultants will measure where you stand, tell you what actually transfers, and size the ramp your volume requires. Free, no obligation.
