Hello Anony,
Thank you for posting question on Microsoft Windows Forum.
Based on your query of looking for having all in one hosting eg 1TB or 2TB, 3TB etc... for unlimited mails to allow your mails being shared the same storage capacity.
Well! Microsoft does not offer a single shared storage pool (like 1TB, 2TB, 3TB) that all your email accounts can use together. In fact, Microsoft's business email hosting works on a per-user license model, and storage is typically allocated per mailbox, not as a single pool of 1TB, 2TB, etc., that all mailboxes draw from.
Regarding Microsoft Exchange Online plans:
- Exchange Online Plan 1 (often included in Microsoft 365 Business Standard): 50 GB per user.
- Exchange Online Plan 2 (often included in Microsoft 365 E3 or E5): 100 GB per user.
For OneDrive storage (1TB–5TB+) which cannot be used for email. It is only for files, documents, backups, etc. So even if you buy a Microsoft 365 plan with 1TB or 5TB of OneDrive, your mailbox still stays 50GB for Exchange Online Plan 1 or 100GB for Exchange Online Plan 2.
For Discounts:
- Microsoft offers lower pricing when you pay yearly instead of monthly. In case you have many users (10+, 20+, 50+), you can negotiate discounts via a Microsoft Cloud Solution Provider (CSP) or a Microsoft partner in country. You can refer to the following articles for more information regarding your concern.
- https://www.microsoft.com/en-us/microsoft-365/exchange/compare-microsoft-exchange-online-plans
- https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support?view=o365-worldwide
Hope the above information clarifying your concern! If it is. Free feel to hit "Accepted" for benefitting others in community having the same query too.