If your Meetup group’s organizer has enabled the group mailing list address, anyone can send a message and Meetup will notify all members who have email updates turned on. To start, check out Mailing list under the More tab on your Meetup group’s page.
If your fellow members aren’t receiving notification of your message, it’s likely for one of these reasons:
Is it your first time using the mailing list?
If so, check your inbox for an email asking you to confirm you wanted to send a message to the entire Meetup group. You’ll need to click the link in that email to confirm and send the message. If you don’t see the email in your main inbox, be sure to check other folders (like Spam).
Are you emailing from the right address?
Your message will only go through if you’re writing from an email address we recognize as belonging to a member of that Meetup group. We do this to prevent spam from reaching Meetup members’ inboxes. So, double-check that you’re using the email address associated with your Meetup account.
Does your email include an attachment that is too large?
Messages sent via the mailing list currently have a total size limit of 2MB. (This limit includes the message itself, plus any attachments.) If your attachment is close to 2MB, there’s a good chance the message won’t send.