While both Exchange 2016 and 2019 are out of support since October 2025, some of our customers who needed more time to finalize migrations to Exchange Subscription Edition (SE) have opted to enroll i...
Updated Apr 15, 2026
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Blog Post
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Announcing Period 2 Exchange 2016/2019 Extended Security Update (ESU) program
Ah, you cheeky.. fellows :) I now understand your reply to my question yesterday. But, i have another one. So, if you didn't buy Phase 1 and you need fixes from February ESU 1 patches, then you cannot really get them. Because you might not release anything for a few months or at all in Phase 2. So, Phase 2 is mostly for those who already had Phase 1 to stay secure and they want another extension. Or, maybe, if you get lucky and there is an update in May, which now seems very likely :)
Nino_Bilic
Microsoft
MicrosoftOur expectation is that indeed, it would be mostly Period 1 customers who would be getting Period 2. I mean if there is an organization out there who really need to sign up for Period 1 now, talk to us (see email) / your account team and we will figure it out.
Our updates are all cumulative so when the next SU under the ESU gets released on [redacted] 😎 this issue will go away because our update packages from Period 2 will also include updates that were released under Period 1.
I cannot say this enough: I'd MUCH rather people not buy any of this and just upgrade.