mailvault365
Microsoft 365 email archiving

The simplest
email archive for
Microsoft 365.

Every user gets searchable access to their own mail forever. Admins decide who can see beyond that. Set up in 5 minutes — no servers, no on-prem infrastructure.

Continue with Microsoft 365

14 days free · then $4 / mailbox / month · no credit card to start

14-day free trial
5-minute setup
No infrastructure needed
Read-only Microsoft Graph

How simple?

Three steps. Five minutes.

No infrastructure to set up. No servers, no agents, no on-prem deployment.

1

Sign in with Microsoft 365

Click the Microsoft login button. Use your existing admin account. That's your sign-up.

2

Approve once

Grant mailvault365 read access to your mailboxes. Standard Microsoft consent flow — takes 30 seconds.

3

You're archiving

Every email — past and future — is automatically archived. Search and download anytime.

Two views, one product

End-user simplicity.
Admin control.

Every user signs in and finds their own mail. Admins keep oversight, manage permissions, and audit access — all from the same product.

Archive / Mailbox

Sarah Mitchell

s.mitchell@contoso.com

Up to date · 2 min ago
Saved Invoices 2026 HR · contracts From legal Attachments only
invoice 2026 ↵
Has attachment

Messages

7 matches · 12,847 archived
RE: Your invoice request — May statement

From: m.morgan@globex-corp.com

May 3
Invoice INV-2026-0412 attached

From: accounts@globex-corp.com

May 1
Your invoice for April 2026

From: billing@cloudprovider.com

Apr 28
Quarterly invoice batch · Q1 2026

From: m.morgan@globex-corp.com

Apr 22
Invoice + delivery note for order #4471

From: supplier@initech.com

Apr 19
RE: Your invoice request — March statement

From: m.morgan@globex-corp.com

Apr 4
Invoice INV-2026-0388 attached

From: accounts@globex-corp.com

Apr 2

Administration

Overview

Contoso Ltd. · live archive monitoring

Sync active · checked 2 min ago

Storage

20 GB / mailbox · pooled

68.4 GB

of 4.94 TB (1.4%)

56,294 messages archived 4.87 TB free

Mailbox health

247 mailboxes total

Manage →
Up to date 240
Syncing 5
Removed 2
56,294
emails archived
68.4 GB on disk
247
active mailboxes
Synced from M365
38
users
Owners + members
12
cross-views (24h)
Logged accesses to non-own mailboxes

Activity

Last 30 days

Emails archived

Last 30 days · daily

+18.4%

Top mailboxes

By storage used

Size Mails
Accounts Payable 14.3 GB
Sarah Mitchell 4.2 GB
Alex Brooks 3.4 GB
David Carter 2.8 GB

How access works

Self-service for users.
Full control for admins.

Most "I need an old email" requests don't need IT. Every employee searches their own archive in seconds — admins decide who gets to see beyond that.

Default for everyone

Default access

Every user signs in with their existing M365 account and finds their own mail. Like Outlook search — but forever, and faster.

Granted by admins

Grant on demand

Need a finance auditor to see the AP team's mailboxes? An office manager their direct reports? Admins grant scoped access in a few clicks.

Always traceable

Always logged

Every cross-archive view, search, and download is recorded with user, time, and target. Built-in transparency for compliance.

Search

One query.
Every mailbox you can see.

Outlook only searches one mailbox. mailvault365 searches every mailbox you have access to — at once — with sender, recipient, attachment, and date filters. Save the queries you run weekly.

invoice 2026 ⏎
Filters Has attachment From: @globex-corp.com Last 90 days Any recipient

24 matches across 6 mailboxes · 1.84 M archived messages searched in 142 ms

Sort: Newest
SM

RE: Your invoice request — May statement

s.mitchell@contoso.com · May 3

Invoice for May attached. Net 2026-05-01 to 2026-05-31, total €4,820.50 incl. VAT — please remit by 30 days …

AP

Invoice INV-2026-0412 attached

accountspayable@contoso.com · May 1

Hi team, attaching invoice INV-2026-0412 for the audit advisory engagement Q1. PO-7741 — same payment terms as …

DC

Quarterly invoice batch · Q1 2026

d.carter@contoso.com · Apr 22

See attached folder — 11 invoices totalling €38,420 covering Q1 2026. All approved by finance, please process …

LB

RE: Your invoice request — March statement

l.bennett@contoso.com · Apr 4

Forwarded as requested. March invoice is the third PDF (2026-03 monthly statement) — flagged the contested line items …

Showing 4 of 24 matches · View all →

Multi-field full-text

Subject, sender, recipient, body — every field is indexed. Boolean operators, exact phrases, partial matches.

Combine filters freely

Stack From + To + has-attachment + date range in one query. Find "all invoices from supplier X with attachments, last quarter" in seconds.

Save and re-run

The query you run every Monday morning? Save it. One click brings it back — never type "from: legal date:>30d" again.

Forensic integrity

Designed for
forensic integrity.

Every archived email is the original RFC 822 message Microsoft Graph delivered — stored as-is, content-hashed, and append-only. The primitives an auditor actually asks for.

INV-2026-0412.eml 412 KB
Verified

Original RFC 822 .eml

OK

Stored exactly as Microsoft Graph delivered it. No re-encoding, no parsed copy.

SHA-256 content hash

match

sha256:a3f4…7c91 · matches store

Append-only message store

OK

No individual message can be modified or deleted — by users or admins. Ever.

Content-addressed storage

OK

Same mail to five colleagues = one storage slot, addressed by its hash.

Audit-logged downloads + cross-mailbox views

OK

Every download and cross-mailbox view recorded with user, time, target.

Archived 2026-05-01 09:14:22 UTC · last verified 2 hours ago

Tamper-evident by construction

Each message is addressed by its SHA-256 hash. If the bytes ever changed, the address would no longer point to that content. No "trust us" — math.

No re-encoding, no lossy parsing

We don't store a "parsed copy." The original byte stream is preserved — every header, every MIME boundary. Restorable to any mail client, decades from now.

Accountability built in

Cross-mailbox access is granted explicitly, scoped per-user, and every view and download is logged. Designed so internal compliance has answers, not guesses.

Why mailvault365

Built for one job. Done right.

Simple by design

No technical setup. No admin certification. The interface is so straightforward you'll get it on the first try.

  • 5-minute setup
  • No infrastructure to manage
  • Self-service onboarding

M365 specialist

We do one thing — Microsoft 365 email archiving. No generic connectors. No second-class M365 support.

  • Native Microsoft integration
  • Works with all M365 plans
  • Microsoft sign-in only

Scope-preserving

Read-only Graph access. Each user sees only their own mailbox by default. Cross-mailbox views are granted explicitly and audit-logged.

  • Read-only Microsoft Graph access
  • Per-customer data isolation
  • Scoped access, every cross-view logged

Built to last

The numbers behind the archive.

RFC 822
Original .eml stored
Every message kept exactly as Microsoft Graph delivered it. Restorable to any mail client, decades from now.
SHA-256
Content addressed
Each message stored under its hash. Same hash = same bytes — tamper detection built into the primitive.
Audit trail
Activity recorded
Every cross-mailbox view, download, and admin action is recorded — visible to your account owner anytime.
Microsoft Graph
Native integration
Direct read-only Graph API. No connector zoo, no second-class M365 support, no third-party broker.

Features

Everything you need.
Nothing you don't.

Auto-sync every 5 minutes

Connect once. mailvault365 polls Microsoft 365 on a 5-minute schedule, so new mail lands in the archive within minutes.

Original RFC 822 .eml

Every email stored as the original .eml — exactly as Microsoft Graph delivered it. No re-encoding, no parsed copy. Restorable to any mail client, decades from now.

SHA-256 content addressing

Every message addressed by its hash. Same hash = same bytes — one storage slot per unique message, integrity preserved by construction.

Search across mailboxes

Search subject, sender, recipient, body — across every mailbox you have access to, in one query. Saved searches recall the queries you run weekly.

Cursor-paginated sync

Microsoft Graph pagination cursors track where each mailbox is up to. Backfilling 50,000-message mailboxes is no different from a 50-message inbox.

Survives user deletion

When a user is removed in Azure, their archive stays — read-only with a "Removed" badge. The whole point of an archive: outliving the source.

Scoped access by default

Each user sees only their own mailbox. Admins grant cross-mailbox access explicitly, scoped per user. Every cross-view is recorded with who, what, when.

Audit-logged access

Cross-mailbox views and EML downloads are recorded with user, timestamp, and target — the trail an internal compliance review actually asks for.

No vendor lock-in

Every archived email is a standard RFC 822 .eml file from day one — never a proprietary format. Download individual messages from any detail page, openable in Outlook, Thunderbird, or any mail client.

Pricing

One simple price.
All features. Always.

No tiers. No "Pro" upsells. The price you see is the price you pay. Per mailbox, billed monthly, cancel anytime.

All features included · 20 GB per mailbox
14 days free · no credit card
$4 / mailbox / month

14 days free · then billed monthly · cancel anytime · no setup fees

What's included

  • Continuous Microsoft 365 archiving
  • Full-text search across every mailbox
  • Personal, shared & group mailboxes
  • 20 GB storage per mailbox
  • Download any email anytime
  • Per-customer data isolation
  • Email support
  • All future features

What you don't pay for

  • Setup fees
  • Per-feature tiers (Basic / Pro / Enterprise)
  • Per-admin or per-seat surcharges
  • Mandatory annual contracts
  • "Premium support" upsells
  • Hidden costs
25 mailboxes
$100 / month
100 mailboxes
$400 / month
500 mailboxes
$2,000 / month
Start your 14-day free trial

No credit card · 14 days free · then $4 / mailbox / month

FAQ

Quick answers.

Your archived emails are stored as standard .eml files (RFC 822) from day one — never a proprietary format. Individual downloads are available from every message detail page; if you need a complete archive export before cancellation, contact support and we'll arrange it.
Your archive is stored on European infrastructure and is yours alone — other customers can never see it, search it, or end up in it. Connections to Microsoft 365 are encrypted. Detailed hosting information is available on request.
No. Everyone signs in with their existing Microsoft 365 account. Your existing SSO, 2FA, and conditional access policies apply automatically.
No. Each user only sees mail from their own mailbox — exactly what they could already access in Outlook. mailvault365 preserves access scope; it never expands it.
No — that's the whole point of an archive. No user and no admin can delete individual emails. The only exception is your account owner permanently removing an entire mailbox archive after the employee has been removed from Microsoft 365 — a deliberate cleanup step, never an automatic one.
Their archive stays. You can revoke their login while keeping the mailbox archived — admins can still search and download from it for compliance and handovers.
No. mailvault365 syncs in the background using read-only Microsoft Graph access. Your users notice nothing — same Outlook, same delivery times.
Yes — every new account gets 14 days free with full access to all features. No credit card required to start. You only enter payment details if you decide to keep using mailvault365 past day 14.
$4 per mailbox, billed monthly, cancel anytime. No setup fees. No minimum commitments. No "Enterprise Plan" upsells.

Other questions? Get in touch →

Ready to simplify your
email archiving?

Try it free for 14 days — no credit card. Then $4 per mailbox per month. Cancel anytime, no setup fees.

Continue with Microsoft 365