Outlook: Email best practices

Tips to help you use and look after your mailbox so it runs smoothly and doesn't get too big

Best practices when using Outlook

1. Outlook Desktop Caching >
2. Search using Outlook for the Web >
3. Review your Storage >
4. Attachments and inserting pictures >
5. Quickly reduce your mailbox size by searching for large emails >
6. Images in Email Signatures >
7. Auto-Archive old messages >
8. Use Shared Mailboxes for a Team or Project >
9. Automatically deleting old messages >

1. Outlook Desktop Caching

   - The more emails you cache, the more likely Outlook Desktop will have problems.
   1. To check and change your caching settings see Outlook Desktop Sync Options >

2. Search using Outlook for the Web

   - Provides near instant results from your entire mailbox compared to Outlook Desktop which initially only gives you results from its cache.
   1. Visit Outlook for the Web at outlook.office.com >
   2. For shared mailboxes see How do I view and add a shared mailbox to Outlook on the Web? >

3. Review your Storage

   - You have 50GB of mailbox storage. Exceeding this limit means you won't be able to send or receive email.
   1. Check your mailbox storage at https://outlook.office.com/mail/options/general/storage
   2. Note that 84% of all diocesan mailboxes are under 10GB (as of May 2024). If yours is over 10GB then use the following tips to help you reduce its size.

4. Attachments and inserting pictures

   - This is the main reason for large mailboxes.

   1. Sending Attachments - The limit is 25MB per message however if it's going to be over 5MB try to reduce the file size and consider using a shared link to it stored in SharePoint or OneDrive.

      1. What to do with email attachments >

   2. Inserting Pictures - If you need to insert a picture into the body of the email, reduce the size of it first.
      1. How do I reduce an image file size? >
   3. Receiving Attachments - If you wish to receive a large file from an external user, create a folder (1 per person) and share to their email address with edit rights.
      1. How do I share/receive a file or folder on SharePoint and OneDrive to/from a colleague or external user? >
   4. Transferring photos or files to your computer - Try not to email yourself photos, instead use these alternatives:
      1. If you have a diocesan mobile, use the OneDrive app to backup photos to your OneDrive to access on your computer. See:
         How do I upload photos taken on my diocesan iPhone / iPad and open them on my diocesan computer? >
      2. Send your photos from your camera to your computer via Bluetooth.
      3. Transfer files from a personal iPhone or iPad using the Apple Devices app:
         How do I transfer files from my personal iPhone or iPad to my work Windows computer >
   5. Outlook is not designed to store files - Yes it can do it but using Outlook as your filing system will affect performance and you may have to eventually delete these files so you can email again. Use SharePoint and OneDrive to store files instead.
   6. Delete attachments or inserted images from emails - If emailing is the only option, save the attached file or inserted image to SharePoint or OneDrive then delete the attachment from the email to reduce your mailbox size.
      1. Saving and removing attachments from emails >

5. Quickly reduce your mailbox size by searching for large emails

   - Trawling through and deleting lots of emails might not necessarily make a significant difference to your mailbox size if the emails themselves are not very big.
   - Instead, to save yourself time and the loss of many email, find the emails with large attachments or inserted images. You don't even need to delete the email, just backup the attached files or inserted images to SharePoint or OneDrive first then remove the attachment or image from the email.
   1. Search and remove large attachments in Outlook Desktop >

6. Images in Email Signatures

   - Avoid inserting images in your email signatures.
   1. 1. Yes they may look pretty but they will increase your individual email size, not by much but multiple that by the thousands of messages and you're increasing your and your recipients' mailbox sizes unnecessarily.
      2. A lot of email providers / programmes block showing images by default. Your recipient may therefore initially see a gap, a red cross or a banner asking to download the image instead of your lovely image.
      3. To change your email signature see: How do I create and add a signature to emails in Outlook? >

7. Auto-Archive old messages

   - Use an Online Archive to automatically move old emails out of your mailbox and reduce its size. The emails will still be accessible to you online and retain a similar folder structure.

   1. Online Archiving >

8. Use Shared Mailboxes for a Team or Project

   - When you and a colleague are working together, instead of duplicating emails in each other's mailboxes, use one shared mailbox that you both have access.

   1. You can request a shared mailbox by raising a support ticket. Include the email address you'd like to use and who should have access.

9. Automatically deleting old messages

   - Like Online Archiving, there is a way for you to set retention policies on folders so that emails get deleted after a certain time period.

   1. How do I automatically delete old messages? >