Multi domain email with shared drive is the operational pattern agency operators reach when running mail for 50+ client brands and looking for shared file storage that doesn't require a separate Dropbox per client. TrekMail Agency at $279/year covers 1,000 client domains × 1,000 mailboxes per domain plus 200GB pooled storage shared across the entire portfolio. The pooled-storage model lets the agency allocate capacity flexibly based on client needs rather than pre-budgeting per client.
Most "multi domain email" comparisons skip the shared-storage dimension. The dimension matters because agencies traditionally stitched together mail (Workspace Reseller, per-tenant) plus storage (Dropbox Business per client) at $25-50/seat/month per client. The bundled approach with 200GB pooled storage at flat $279/year reverses the per-client cost math entirely.
This guide walks the pooled-storage math, cross-domain ACLs, and pricing comparison against Workspace Reseller. For the broader frame see agency email hosting.
What Multi Domain Email With Shared Drive Actually Covers
Multi domain email with shared drive in TrekMail Agency bundles mail for 1,000 client domains plus 200GB of Drive shared across the entire portfolio. The agency operator allocates capacity per client based on actual need rather than pre-committing fixed quotas per client at signup time.
The combination matters for agency economics. Per-tenant storage allocation creates the same per-client cost overhead that per-tenant mail allocation does — the agency pays for unused capacity at low-volume clients and runs short at high-volume ones. Pooled storage lets the actual usage shape the allocation without per-client procurement decisions.
The 200GB Pooled Storage Math
The 200GB pooled storage in multi domain email with shared drive at the Agency tier covers typical operations. A 100-client agency averaging 2GB per client uses 200GB at capacity. The math leaves headroom for variation across clients without per-client cap negotiations.
Beyond 200GB, the Drive Add-On slider extends storage at $0.015/GB/month floor. Adding 500GB costs $7.50/month or $90/year. Adding 5TB costs $75/month or $900/year. The add-on extends the same pooled model rather than creating per-client buckets, which keeps the operational simplicity of one storage pool across the portfolio. See multi-domain email hosting for the broader operator frame.
Cross-Domain Shared Folder ACLs
Cross-domain shared folder ACLs in multi domain email with shared drive let an agency operator grant access to specific clients from the same Drive pool. A "Q3 Campaign" folder created in the agency's main account can be shared with clientA.com and clientB.com mailboxes simultaneously. The same identity that authenticates each client's mail authenticates their Drive access.
The ACL model is what makes the pooled storage operationally useful at agency scale. Without cross-domain ACLs the agency would need separate Drive instances per client; with them the agency runs one Drive with per-client permission boundaries. Adding a new client means provisioning their mail account and granting Drive access to relevant folders — a few minutes per client rather than a separate Drive subscription per client.
Per-Tenant Drive Add-On for Heavy Clients
Per-tenant Drive add-on in multi domain email with shared drive setups handles clients whose storage needs dramatically exceed the pooled average. A video production client needing 2TB of dedicated storage gets their own Drive add-on attached to their domain. The add-on is add-only, not subtract-from-pool, so the agency's 200GB pooled storage stays intact while the client gets dedicated capacity.
The pricing model passes through cleanly. The agency charges the client $0.020-0.030/GB/month including margin; the underlying vendor cost is $0.015/GB/month. The margin spread is healthy and the add-on scales with client need rather than requiring renegotiation of the agency tier. Heavy clients fund their own storage; the pooled tier covers the rest.
Comparison vs Workspace Reseller Pricing
The Workspace Reseller alternative to multi domain email with shared drive prices per tenant per seat. A 100-client agency averaging 5 seats per client and reselling Workspace Business Starter at the standard $6/seat/month pays Google $36,000/year. The same agency on TrekMail Agency pays $279/year for the entire portfolio plus optional add-ons for heavy clients.
| Model | 100 clients × 5 seats avg | Storage pattern | Annual cost |
|---|---|---|---|
| Workspace Reseller | $36,000/yr (500 seats × $6) | 30GB per seat = 15TB total but per-seat boundaries | $36,000 |
| TrekMail Agency + Drive add-ons | $279/yr + $300/yr add-ons for 2 heavy clients | 200GB pooled + per-client add-on | $579 |
The math gap at 100-client scale is 60x in favor of the TrekMail bundled approach. The gap widens at higher client counts because per-seat models scale linearly with seats while flat-rate stays constant within the tier cap. The multi domain email with shared drive bundled model is what makes flat-rate agency economics work at meaningful scale.
Three Agency Use Cases the Bundle Fits
Three agency use cases fit multi domain email with shared drive cleanly. Marketing agencies running cold outreach for 50-200 clients: mail + light Drive usage for campaign assets. Web development agencies maintaining 30-100 client domains: mail + Drive for development files and client deliverables. MSP-style email management for SMB clients: mail focused with Drive as a complementary service customers expect.
Each use case benefits from the pooled-storage flex differently. Marketing agencies use light Drive across many clients (averages out to small per-client usage). Web dev agencies have variance — some clients with 5GB of project files, others with 200MB. MSPs treat Drive as an attached service customers might use at 10GB per client. The pooled model accommodates all three patterns without per-client procurement.
Where TrekMail Agency Fits in This Pattern
TrekMail Agency at $279/year is the platform position for multi domain email with shared drive at agency scale. The tier covers 1,000 client domains × 1,000 mailboxes per domain × 200GB pooled Drive. Per-customer DKIM runs automatically; the API supports scripted provisioning.
The honest disclosure: TrekMail doesn't include productivity tools (Docs, Sheets). Agencies whose clients specifically request branded Workspace or Microsoft 365 should resell those alongside rather than substituting. For mail-focused agency operations with file-sharing needs, the bundle is the structurally cheapest approach at portfolio scale. See unlimited email accounts hosting for the broader unlimited-mailbox frame.
Next Steps
The honest multi domain email with shared drive pick for agency-scale operations is TrekMail Agency at $279/year with the Drive add-on slider for heavy-storage clients. The flat-rate pricing means cost stays constant from 50 to 1,000 client domains within the tier cap. Workspace Reseller alternatives produce 60-150x higher bills at typical agency scale.
Test TrekMail at trekmail.net/pricing — no card required for Nano. Agency at $279/year covers the full multi domain email with shared drive bundle for agency-scale operations. See centralized email management for the dashboard patterns at multi-tenant scale.
One concrete example: a digital marketing agency in Toronto running cold-outreach for 80 SMB clients. Before TrekMail they used Workspace Reseller at $6/seat — 80 clients × 4 seats average = 320 seats × $72/year = $23,040/year. After switching to TrekMail Agency with the pooled-Drive bundle, total spend dropped to $279/year, freeing $22,761/year for additional contractor capacity or margin expansion across the agency operation.
A second example: an MSP servicing 150 small-business clients with mail-and-storage as a packaged service. Their old setup mixed Workspace Reseller for some clients ($14,400/year) and Microsoft CSP for others ($18,000/year). Consolidating both cohorts onto TrekMail Agency brought total platform cost to $279/year plus a few Drive add-ons for heavy clients. Total annual saving: roughly $31,000 across the consolidated base, freeing substantial margin for the MSP's other operational priorities.
A third example worth flagging: a creator agency in Lisbon managing mail and assets for 40 YouTube creators. Each creator gets their own custom-domain mailbox plus shared folders for video drafts, thumbnails, and brand-deal assets. The agency previously paid Workspace ($2,880/year) plus Dropbox Business ($7,200/year). On TrekMail Agency the same workload costs $279/year plus a 2TB Drive add-on at $360/year for the four creators producing 4K video content. Total: $639/year versus $10,080/year — a 16x cost reduction.
The pattern across all three examples is the same: flat-rate pricing reverses the per-tenant cost economics that per-seat resellers depend on. Agencies at 50+ client scale who run the math on their current stitched setup typically discover savings in the $20,000-50,000/year range — meaningful margin recovery that compounds across the multi-year horizon.
One practical note on Drive quota management for multi domain email with shared drive operations: monitor the pooled storage usage monthly rather than waiting for alerts. The 200GB pooled cap covers typical agencies comfortably, but a few heavy clients can consume disproportionate storage without obvious signals until the pool hits 90% capacity. Setting a personal calendar reminder to check the storage dashboard on the first of each month takes two minutes and prevents the scramble of discovering a near-full storage pool just before onboarding a storage-intensive new client who expects immediate access to their shared Drive resources right at onboarding time.
