When importing a load of messages into Gmail they have all been marked as unread. I don't want to have to go through 15000 emails page by page to mark them as read, is there any way to do this in bulk?
Search for string
before:date (date in format
yyyy-mm-dd) and then choose More > Mark all as read.
Watch out: This will select also emails from this date! I.e.
before:2012-07-12 will select email received before 12 July 2012, but also emails received on 12 July 2012.
Search your email with
And then select them all and mark as read
label:unread AND before:DATE
in the search bar.
label:unread AND before:2016-09-30
Then click on the checkbox (top left) above the message and select ALL.
Click the "Select all conversations that match this search" link that appears above the first message.
Click More> Mark as Read.
You could also use this Google script which automatically marks emails in any Gmail label (inbox also) as read when they become older than N days. Google script to mark old emails as read.
Please note that it is not a one time activity but rather a continuous "check and mark as read" script.
Open the label (or, your Inbox, or Sent Mail, etc) containing the messages you'd like to select. Click the Select: All link above your messages. Click the link that says Select all [number] conversations in [current view]. Select the action you'd like to do