FAQ - Sending Emails with large attachments

Modified on Wed, 31 Jan at 1:13 PM

Hi all,


We’ve had a few queries/issues recently around sending emails with large attachment sizes to external recipients, so I wanted to address a few of the common questions.


What Email system do we use?


We use Microsoft Office 365, which is also used by most schools in the Peterborough area.

This is a bleeding edge system that is constantly under development by Microsoft & we receive new features extremely quickly.


What is the maximum size of attachments sent?


We use the Office 365 defaults, which allows for attachments of up to 35mb.


Can we increase this?


Yes, we can increase this to 150mb – However, we stick with the defaults as most other organisations will be on the defaults or less.

Below is a quick table showing the defaults for the most common providers.



Max Size

Office 365 


Google (Gmail)






(Most UK Businesses & schools use 365 or GMail)


This means that even if we increase our maxmium attachment size, your email will be rejected by the recipents email server.

Obviously, we do not have access to change other organisations defaults.


Do this limits apply when scanning?

Yes. If you “Scan to email” you will get hit by this limit as scans are first sent externally from the photocopiers to Office 365 & then back to you.

However, if you “Scan to onedrive” the scan can be any size as this goes directly into your onedrive. If you need support with this, please let us know.


How do I send files that are bigger than 35mb?


There are three methods


  • Sharing to a verified organisation/School via Onedrive/Sharepoint (Preferred)
    Just like when you “Share” a link with someone inside the school, Staffmembers (Not students) are able to share files directly with external users – Instead of sending the actual file, this gives the external person access to the file, directly in your Onedrive
    For instructions on this, please use the link below


    You can also upload files from home directly to your Onedrive, instead of sending them to yourself. This is useful if you are working on a personal device – For example, an iPad, laptop or Chromebook.

    Note:- We only allow with organisations that we have verified are secure, to ensure that we are protected under the GDPR.
    For a list of organisations, please see here https://kscsitservices.freshdesk.com/a/solutions/articles/43000693909

     If you wish to share with any organisation that isn’t on this list, please log a ticket in the usual way.
  • Shrinking the attachment down below the max size
    The majority of the time, It’s possible to strink the file size down by running through some compression software, or saving the file at a lower quality.
     PDF’s are incredibly easy to shrink (A 110mb file can normally be squeezed down below 15mb)
  • Uploading to the KSCS Website
    IT Services are able to upload files to the KSCS website & then provide a link. 



Can we use Google Drive instead of Office 365 to share?


Our IT infrastructure is based around the Microsoft Office 365 platform, as we have invested quite heavily into it & have backups, training/security & retention in place to comply with legal requirements.

Additionally, uploading Microsoft Office based files to Google Drive converts them to Google format which heavily modifies the formating. It also attempts to share via gmail, which to avoid duplication/confusion we don’t support.
 Onedrive & Sharepoint are essentially identical to the Google platform, with some slight differences. 


Thanks – But I’m still confused, can you help?

Absolutely – Please log a ticket on the IT Service desk at ITServicedesk@kscs.org.uk

Please let us know in advance of any time critical work to ensure that we have time to adaquately resource & support you (Eg if work is exam based!)


I hope this helps, but any queries, please let us know.

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