It’s annoying and a little worrying when your calendar fills up with invitations from strangers. Before you panic, know this is a common problem with a few predictable causes and several straightforward fixes. This guide explains why it happens, the risks, and practical steps you can take right now to stop it and protect your calendar.
How the calendar invites work?
Most calendar systems, like Google Calendar, Outlook, Apple Calendar, etc., usually accept invitations sent using the iCalendar format (files or email invites with an .ics file). When an invite arrives, the calendar service can:
– Add the event automatically,
– Show it as a tentative event, or
– Wait for you to accept/decline.
Different services have different default behaviors, and that’s part of why unwanted invites sometimes appear on your calendar without much interaction.
Some Common and Possible Reasons (for Getting Calendar Invites from People I Do not Know)
1. Promotional invitation
Sometimes spammers send calendar invites to advertise sales, events, and also scams. Because those invitations look like emails but can appear directly on your calendar, and by the way, spammers exploit that visibility.
2. Invitation with phishing or malicious links
Some invites contain links or attachments that could lead to stealing your valuable credentials or installing dangerous malware. The invitation itself might be harmless, but it is more dangerous when it points to a malicious RSVP page.
3. Compromised accounts
If someone’s account (a sender or a contact of yours) is hacked, that account can be used to send invites to many addresses- including yours.
4. Public or shared calendars
If your email is associated with a public calendar subscription, or you’ve previously accepted shared calendar invites, spammers can sometimes add items to those calendars or use similar names.
5. Scrapable emails or addresses
Usually spammers buy or scrape emails and sell the lists on the dark web. If your address is public on a website, forum, or social media, it’s easy prey. If you suspect this issue you can send us a quote for the dark web monitoring.
6. Sales or marketing tools
Some legitimate mailing tools create calendar invites as part of outreach (webinars, product demos). If you’re listed as a lead anywhere, you might get calendar invites from services you don’t recognize.
What are the risks of spamming calendar invites?
Here we have listed some risks for the spamming calendar invites.
1. Phishing/credential theft via links that ask you to “confirm” or “download.”
2. Malware from attachments or websites linked in the event.
3. Privacy leakage if the event reveals your calendar availability to the sender or others.
4. Calendar clutter that hides your real events or causes missed appointments.
Immediate actions for malicious calendar invites
– Don’t click links or download any attachments from those invites that you do not know.
– Don’t accept or respond to suspicious invites. Accepting can signal that your address is active.
– Remove the event from your calendar (delete/unsubscribe)—see service-specific tips below.
– Mark the email as spam/phishing in your mail client if the invite came via email.
– Block the sender if possible whenever it is identifid.
Or you can see this video for better understanding 👇👇
How to stop or limit these invites?
Google Calendar
Open calendar.google.com → click the gear icon → Settings → Event settings.
Change “Automatically add invitations” to “No, only show invitations to which I have responded.”
Under “Events from Gmail,” you can turn off automatic creation of events from Gmail.
In Gmail,
mark invitation emails as spam or
Use filters to auto-delete invites containing suspicious words (e.g., ‘RSVP,’ ‘webinar,’ or strange domains).
Check Google Account > Security for suspicious connected apps and revoke access.
For Outlook or Microsoft 365
In Outlook (web version):
– Go to Settings at first → View all Outlook settings → Calendar → look for options like ‘Automatically accept meeting requests’ or ‘Add invitations to calendar’ and set to manual or only from contacts.
– Mark malicious invite emails as Junk.
– Create an inbox rule to move invites from unknown senders to a separate folder.
For the Apple Calendar (iCloud / macOS / iOS):
On macOS Calendar:
Go to Calendar → Preferences → Advanced and uncheck options that auto-add invites from Mail, or set Mail to not detect the calendar invitations automatically.
In iCloud.com:
From the calendar options, you can unsubscribe from unknown calendars and delete events.
On iPhone,
Consider disabling automatic mail-to-calendar conversion or
Remove the calendar event and block the sender in Mail.
Note: Exact menu names can vary slightly with iOS updates. If you can’t find the setting, search within your calendar app’s preferences for phrases like ‘invitations’ or ‘automatically add.’
Long-lasting plan and security tips
Do not forget to
– Enable the 2-factor authentication, or 2FA, on your email and calendar accounts.
– Change passwords and use a password manager if you want.
– Revoke third-party app access in account security settings. Because the apps with calendar permission can sometimes be abused.
– Keep your email address hidden on public pages as much as possible, or use a contact form if needed.
– Try to use a separate email for public sign-ups and newsletters. Keep your main email private for important accounts.
Create email filters that quarantine invites from senders not in your contacts or from untrusted domains.
Educate your team (if using a work email) about such spam—attackers often target business addresses.
How can you understand if an invite is legitimate?
At first you need to check the sender’s email address carefully. Have a deep look for typos in domains (e.g., gooogle.com) or any other suspicious domains. Hover over links (on desktop) to see where they could go before clicking. Contact the supposed sender by another channel (phone or known email)—do not use contact details provided inside the suspicious invite.
Take a deep look at event details and typos, like vague descriptions, urgent-sounding language, and requests for credentials. Those are red flags. Stay alert about this.
Quick checklist (copy this for future awareness)
– Don’t click links in unknown invites.
– Delete or decline suspicious events.
– Mark the invite email as spam/phishing.
– Block sender and/or unsubscribe.
– Turn off the ‘auto-add’ invites in calendar settings.
– Enable 2FA, change the passwords, and revoke app access.
– Use filters to quarantine invites from unknown senders.
FAQ
Q: Is it safe to decline an invite?
A: Yes—declining is safe. But in some services declining might notify the sender. If you’re unsure, remove the event from your calendar without responding.
Q: Can calendar invites contain malware?
A: The .ics file itself is usually harmless text, but invites often include links. Those links can lead to phishing pages or downloads; don’t click them.
Q: Why do these show up on my phone, too?
A: Your calendar syncs across devices. Once an event is in your account, it will appear on all devices connected to that account.
Q: Will blocking the sender stop the future invites?
A: Sometimes. Spammers often change addresses, so filters and settings (like disabling auto-add) are more reliable.
To wrap up,
When you get this kind of invitation, you need to stay calm, then act. Unwanted calendar invites are a nuisance, but you can stop them and protect your account by changing a couple of settings and security habits, like turning off auto-add, tightening email filters, enabling 2FA, and being cautious with links. Do the quick checklist above today, and your calendar will be tidy again. If you will follow the quick checklist (as discussed) the endpoint security rules will be followed automatically.
Stay alert, stay safe.
