Nexus Email
Nexus is the University’s instance of the cloud-based Microsoft Office 365 service, providing email, calendaring, and access to a range of other Office 365 applications.
Information about accessing email can be found on the IT Services website.
Multiple Oxford and affiliations and email addresses
If you have multiple affiliations (and hence multiple university email addresses for receiving mail), the Nexus sending email address will typically be set to your college address (firstname.lastname@collegename.ox.ac.uk) or other unit/department address. If you only have a Maths affiliation then your Nexus sending address will be set to your firstname.lastname@maths.ox.ac.uk address.
Changing your primary address
Although you can receive email to multiple addresses, you can only send from a single email address.
The IT registration self-service tool currently does not work for Maths addresses, so if your Nexus sending address is not the one you prefer to use, you should open a request with the IT Services helpdesk who will change it for you.
Warning (Dec 2025): Some people have reported a problem where they are unable to receive email after changing their primary email address to their Maths address, each requiring intervention from the Nexus team to resolve. IT Services are investigating this issue, but in the meantime we recommend you don't change your primary address if you are expecting any important emails.
Sending from an alternative address via SMTP
Nexus only supports sending from your primary/preferred email address, and when using the web interface or new version of Outlook, that is the only option available.
If you need to send from multiple personal addresses (i.e. your department and college addresses), a possible workaround is to use a desktop/mobile mail client such as Thunderbird and configure it to send email via the university SMTP server (smtp.ox.ac.uk) instead of the Nexus SMTP server (outlook.office365.com).
Please note that we can only provide limited support for this - it is not officially recommended!
The settings would typically be:
Server: smtp.ox.ac.uk
Port: 587
Encryption: STARTTLS
Username: Your SSO username without the @OX.AC.UK part (e.g. abcd1234)
Password: Your SSO password
However, please be aware that IT Services recommend using the Nexus SMTP server these days, so there is no guarantee that this will continue to work in the long-term.
Short-form aliases
Please do not use the following short-form aliases:
- Maths short-form aliases (
mathsusername@maths.ox.ac.uk) can no longer be used to send email. They will cease to work in the medium-term, when the legacy Maths email infrastructure is fully decommissioned, so you should migrate everything to your official @email address. - Your SSO address (
ssousername@ox.ac.uk) cannot be used to send email, and as this is not your official email address, it should not be assumed to persist in the long-term.
Spam filtering
There are multiple layers of spam filtering applied to incoming emails:
Microsoft
- The University has no control over Microsoft's in-built spam filtering rules, which are not documented or specified by Microsoft in a way that customers can easily understand. As a result, legitimate mail may occasionally end up in users' spam folders. Individual users do have some control over spam filtering by marking messages as spam or 'not spam,' which is useful for improving accuracy.
- Information on how spam and junk email is processed, and how you can use junk email filters can be found here: https://help.it.ox.ac.uk/guidance-on-spam-and-junk-email
The University
- InfoSec’s webpage provides information on the current security measures the University applies to email, including filtering: https://infosec.ox.ac.uk/email
- The University's email security scanning system can act retrospectively, occasionally removing messages it deems harmful from a Nexus365 mailbox, even after they have been delivered and read.
- Information on how to access and check your Nexus365 quarantine and release email from it into your mailbox can be found here: https://help.web.ox.ac.uk/nexus365-email-quarantine
Users
- Information on using rules to automatically perform specific actions on email that arrives in your inbox can be found here: https://support.microsoft.com/en-us/office/manage-email-messages-by-using-rules-in-outlook-c24f5dea-9465-4df4-ad17-a50704d66c59
Rate limits and quotas
- There are reports that SMTP connections to Nexus365 are sometimes throttled too heavily. This may affect non-Outlook mail clients using these open standards and protocols and could impact attempts at bulk-sending. Nexus365 email is not intended for use as a bulk-sending service. The official rate limit is 30 messages per minute to ensure that any compromised account can only cause limited damage.
- More information on Microsoft sending limits: https://learn.microsoft.com/en-us/office365/servicedescriptions/exchange-online-service-description/exchange-online-limits#receiving-and-sending-limits
- The mailbox quota is determined by the user's license, typically 100GB. If the mailbox exceeds this quota, email archiving can be enabled. For more information, visit: https://help.it.ox.ac.uk/in-place-online-archive
- Items in Deleted Items are automatically removed after 120 days via an overarching retention policy that cannot be changed on an individual level.
Leaving Oxford
When your university card expires, your SSO and Nexus email will be closed down automatically. Please be sure to export any emails you need to keep, notify your contacts, and download/transfer any files stored in your OneDrive in plenty of time. For more details, see Finishing IT use at Oxford.
If you are a researcher, you may wish to create an ORCID (Open Researcher and Contributor ID) profile to help communicate your latest contact details.
Support
Nexus-related support requests can be raised directly with the central IT Services helpdesk. Departmental IT support will advise where they reasonably can, but have no control over the Nexus service and very limited management tools to inspect issues.