Exchange Online limits

Timelines and exceptions · All guidance changes

Exchange · Official Microsoft guidanceObserved changes retained

Observed content change

1 new passage (about 30 words), 1 edited passage (5 words changed). The changed wording mentions supported platforms. Review the source to confirm the effect.

May need admin actionCheck the platforms and versions you run.

Support wording

EditedMailbox folder limits

… that can be supported in Exchange ~~[removed: Online.]~~ [added: Online and Exchange Server SE.] The goal of these limits is …

NewMailbox folder limits

[added: Note These limits apply to any and all folder types, meaning system-created and user-created alike irrespective of whether they're located in user-owned mailboxes or Exchange] …

Short quotes of Microsoft's changed wording from Microsoft source, © Microsoft Corporation. Read the page for the full text.

Read the current Microsoft source · Link to this observation · Compare any two versions

Sections to inspect

Mailbox folder limits

Up to 12 section headings from retained before/after evidence. The current source may have changed again.

Why this was flagged

The changed words, with a few words around them, matched these rule categories: supported platforms. These matches identify subjects to assess; they do not establish a policy change or applicability.

Observation details · observed 19 Oct 19:09 UTC

Observed by ChangeIntel: 19 Oct 19:09 UTC
Source update metadata: 19 Oct 17:34 UTC
First observed on this installation: 5 Oct 17:20 UTC
Last successful check: today 07:19 UTC
Next check due: today 13:19 UTC

Observation time is not publication time, and a comparison does not establish an effective date. Full source bodies are not published; this page holds generated summaries, section headings and, as the page's license allows, Microsoft's changed wording. A documentation edit does not confirm feature availability in an environment.

Watch this page to review its changes in My radar.

Timeline

From the capture of 19 Oct 19:09 UTC

1 relative period
15 undated sections
17 with conditions

Settings and overrides named on this page

Registry values, policies and cmdlets the source mentions, with the dated steps that name them. Read the source for the values to set.

MaxAttachmentSize
MaxRequestSize
MaxSendSize
MS-Exchange-Inbox-Rules-Loop
MS-Exchange-Transport-Rules-Loop
Remove-Mailbox

Relative periods

Counted from an event the source describes, such as installing an update; they are not calendar dates.

within 30 daysRetention limitsException
Remove-Mailbox

Requirements, exceptions and scope

GuidanceScopeRecommendation1 condition3 passages
Find the Exchange Online limits for various service areas, including address book limits, mailbox storage limits, and reporting and message trace limits, to name just…
Capacity alertsRequirement1 condition1 passage
Distribution group limitsRequirementScope2 conditions2 passages
Distribution group limits across standalone optionsScope1 passage
Hold limitsScopeRecommendation1 passage
Journal, transport, and inbox rule limitsExceptionScope4 conditions5 passages
MS-Exchange-Inbox-Rules-LoopMS-Exchange-Transport-Rules-Loop
Mailbox folder limitsRequirementExceptionScope4 conditions2 passages
Mailbox folder limits across standalone plansScope3 conditions1 passage
Storage limitsRequirementExceptionRecommendation11 conditions1 passage
Storage limits across standalone plansRequirementException8 conditions1 passage
Message limitsRequirementScope1 condition2 passages
MaxAttachmentSizeMaxSendSizeMaxRequestSize
Message limits across standalone optionsException1 condition1 passage
Receiving limitsScope1 passage
Sending limitsExceptionScopeRecommendation5 conditions4 passages
Sending and receiving meeting invite limitsException2 conditions1 passage

Extracted automatically from Microsoft's wording. Confirm dates, conditions and whether they apply to you in the source before acting; a month or quarter is a window, not a day.

Observed history and review priority

Captured 19 Oct 19:09 UTC; extracted 19 Oct 19:09 UTC. Extractor: microsoft-1/9/fc65ebeb286710c0a830833db8a7e5de7e266b79981fe9c7c34479be9369ad3c.

Review priority. Previously extracted guidance is missing from a later capture · Extracted assertions require review · Applicability or exceptions require review

0 date changes and 0 condition changes across 2 compared revisions. Suggested check interval: 6 hours.

Earlier unavailable versions and edits between checks are unknown. A missing statement requires review; it does not mean the policy was cancelled. Recovered historical statements are not original revision snapshots.

Retained observations · 4

Compact evidence remains available after full document bodies expire. Earlier extractions can have different vocabulary or capture limitations.

19 Oct 19:09 UTC · 36 candidates
12 Oct 19:35 UTC · 36 candidates
6 Oct 17:27 UTC · 38 candidates
5 Oct 17:20 UTC · 38 candidates

No related evidence found in this installation's recent collection. This does not establish that no announcement exists.

Retained observations

19 Oct 19:09 UTC · shown above
12 Oct 19:35 UTC
8 removed passages (about 50 words). The changed wording mentions prerequisites. Review the source to confirm the effect.
6 Oct 17:27 UTC
Source metadata changed; retained article content is unchanged.
5 Oct 17:20 UTC
Baseline for retained history; no earlier retained text to compare.

What changed

First observed 18 Oct 2026

No field changes in the recorded history.

Cite this recorded revision to keep the same title, summary, facts and links when the page changes.

A day selects the latest observation by the end of that UTC day; today's selection can change until midnight. History starts when this installation records it.