Sending file attachments in Outlook email from Sharepoint Document library

For the specific need of sending many files via Outlook, SharePoint document libraries work well without requiring a third‑party add‑in, and they also help avoid large attachments by using links instead of files.

Key points based on the described scenario:

1. Attaching from SharePoint/OneDrive in Outlook (no add‑in required)
   In the new Outlook and Outlook for Mac, files stored in OneDrive or SharePoint appear as cloud locations when attaching:
   • In new Outlook: use Attach File → choose from OneDrive or SharePoint locations. Outlook then lets sending either:
     • A link (recommended, keeps email small, centralizes the document), or
     • A copy of the file as a traditional attachment.
   • In Outlook for Mac: use Attach File → Browse Cloud Locations to pick files from OneDrive/SharePoint, or use Insert Hyperlink if there is a URL to a folder or file.
   This works with multiple files (e.g., 12 monthly statements) and does not require harmon.ie.
2. Handling large or blocked attachments
   When files are large or of a type Outlook might block, Microsoft guidance is to store them in OneDrive or SharePoint and send a link instead of attaching the file directly:
   • Upload the PDFs to a SharePoint document library (or OneDrive for Business).
   • In Outlook, insert them as links from those cloud locations. This avoids size limits and blocked attachment types and keeps a single source of truth.
3. SharePoint vs. OneDrive for the filing system
   The choice between a flat, metadata‑driven SharePoint library and a traditional folder structure in OneDrive is about information architecture, not about Outlook integration:
   • Outlook can attach from both OneDrive and SharePoint using the same Attach File → OneDrive/SharePoint experience.
   • For a firm‑wide, client‑centric repository (multiple staff, shared access, permissions, retention, and views by client/year/account), SharePoint document libraries are generally better suited than personal OneDrive folders.
   • With SharePoint, it is possible to:
     • Store documents in a flat or lightly‑nested structure.
     • Use metadata (Client, Account, Year, Document Type, etc.) and views instead of deep folder trees.
     • Still easily select multiple files and share them via Outlook as links.
4. Practical sending patterns for the firm
   A workable pattern without extra cost:
   • Store all client documents in SharePoint libraries (with metadata and views to replace complex folders).
   • When emailing:
     • From Outlook: Attach File → pick from OneDrive/SharePoint and choose Send a link (or Send a copy if absolutely required).
     • From SharePoint: open the document library, select multiple files, use Share/Copy link (permitted by context via SharePoint/OneDrive sharing guidance) and paste the link(s) into Outlook.
   • For very large sets of files, consider sharing a folder or a view (e.g., “Client X – 2024 Bank Statements”) via a single link instead of attaching 20 PDFs.

Given the business size and the need for structured, shared client records, a SharePoint document library with metadata is appropriate. Outlook already supports attaching and sharing files from SharePoint/OneDrive, so there is no technical need to stay with a traditional folder system in OneDrive solely for email‑attachment reasons.

References:

• Add pictures or attach files to emails in Outlook
• Attach a file or folder to a message in Outlook for Mac
• Blocked attachments in Outlook
• Reduce attachment size to send large files with Outlook