PanicStation.org
UK USA
uk Work & employment crises colleague aggressive messages • coworker hostile texts • aggressive emails after hours • bullying by messages • harassment outside working hours • out of hours work messages • threatening coworker messages • abusive slack messages • angry teams messages • late night work contact • colleague texting personal phone • work chat intimidation • coworker crossing boundaries • escalating workplace conflict • unwanted contact from colleague • hostile tone from coworker • after work harassment • bullying outside workplace

What to do if…
a colleague starts sending aggressive messages outside working hours

Short answer

Stop engaging right now, preserve the messages, and raise it promptly with your manager or HR so it is formally logged. If there is any threat of violence or you feel unsafe, prioritise safety and contact emergency services.

Do not do these things

  • Do not reply in anger or try to “win” the argument in writing.
  • Do not delete messages or “tidy up” the chat history.
  • Do not meet them alone to “clear the air” if you feel intimidated.
  • Do not share screenshots widely at work or on social media (it can inflame things and breach policies).
  • Do not assume it will “blow over” if the tone is escalating or repetitive.

What to do now

  1. Create a calmer pause. Put the conversation on mute and turn on “do not disturb” for that contact. If any message suggests immediate harm, call 999 and get to a safer place first.
  2. Preserve evidence (before you block or change settings). Take screenshots that include names, dates, and times. If it’s a chat app, export or save the conversation if that feature exists. Keep a simple log: date/time, what was said, and how it affected you.
  3. Stop using personal channels. If they’re contacting your personal number or social accounts, switch to work-only communication (work email/work chat) and silence personal channels after you’ve saved what you need.
  4. Send one boundary message only (optional, and only if it feels safe). Example: “I’m not available outside working hours. Please keep messages work-related and respectful. We can address this in working time.” Then stop replying.
  5. Report it promptly to the right person. Tell your line manager and/or HR and ask for it to be recorded as a bullying/harassment concern. If your manager is involved or you do not feel safe raising it with them, go to HR or another manager named in your policy.
  6. Use your workplace process (informal or formal) rather than private negotiation. Many issues are handled first by raising it informally, but if it feels unsafe, severe, repeated, discriminatory, or you’ve already tried informal steps, it may be appropriate to raise a formal grievance. Follow your organisation’s policy and keep your report factual.
  7. Use your right to support in formal meetings. If you’re invited to a formal grievance meeting (or an appeal hearing), ask to bring a “companion” (usually a trade union representative or a work colleague). Confirm this in writing when the meeting is arranged.
  8. If it overlaps with discrimination or hate incidents, flag that clearly. If the aggression includes comments linked to a protected characteristic (for example race, sex, disability, religion), say so when reporting it and keep the messages.
  9. If it’s moving into threats or stalking, escalate outside work too. If contact continues despite boundaries, involves intimidation, or you fear for safety, consider reporting to police (999 in emergencies; otherwise 101) and tell your employer you’ve done so.

What can wait

  • You do not need to decide now whether to take legal action, resign, or “forgive and forget”.
  • You do not need to write a perfect statement tonight—capturing and saving the messages is the key first step.
  • You do not need to confront them face-to-face to prove it’s serious.
  • You can decide later whether to block them everywhere (save evidence first, then choose what helps you feel safe).

Important reassurance

It is normal to feel shaken, angry, or unable to sleep after aggressive out-of-hours messages. Taking a pause, keeping evidence, and moving the problem into a documented workplace process is a sensible, protective response.

Scope note

These are first steps to stabilise things and prevent escalation. Longer decisions (formal complaints, mediation, legal steps, changing roles) can come later, ideally with support.

Important note

This is general information, not legal advice. If you feel in immediate danger, call 999. If you’re unsure how to raise this safely at work, you can get independent guidance and consider speaking to a union representative or an employment adviser.

Additional Resources
Support us