Gmail Date Searching

In your Gmail search bar, enter the following search operator:

after:YYYY/MM/DD
before:YYYY/MM/DD

To ensure you are searching for a specific date, the date you set in the before operator should be one day later than the date set in the after operator.

Tip Source: Emailanalytics.com

Gmail Doesn't Receive Emails Frequently Enough from My External POP3 Email Account

This article from Lifehacker (Make Gmail Check Your POP Accounts More Frequently)
helped me solve an ongoing problem where Gmail was only checking a branded, external email address (POP3 mailbox) about once an hour.  Clients and prospective clients were sending me emails to collaborate on projects and I wasn't receiving anything right away.  Emails were taking 10-60 minutes to be retrieved.

It was frustrating to have to go to Settings > Accounts and Import and manually tell Gmail to fetch more mails from my email address at another domain.

There's also this option in the Labs options section. [source]

Flushing out an Overflowing Gmail Inbox with Targeted Gmail Searches

If you're like me, you may have accumulated dozens of subscriptions that arrive in your inbox daily. Even though it may not seem like much, over months or years, these unread emails can become overwhelming and hard to delete in bulk unless you can find a way to filter them with a search.

Update 4/6/25:

in:inbox is:unread has:nouserlabels 

Finds everything that is unread and has no user labels. Helpful for collecting and deleting unread, unorganized emails in bulk.

Update 5/4/20:

Two new and improved searches to clear out old messages in Gmail

in:inbox is:unread has:nouserlabels NOT label:important NOT is:starred
(The new key search operator (has:nouserlabels) will hide all messages from the search that have a user assigned label.  I almost always apply either an important label or a personal label to messages that I need to save for future use.)

in:inbox is:read has:nouserlabels NOT label:important NOT is:starred
This will show read messages that still do not have personal labels applied.  These messages are likely ones that were opened, read, and then never deleted.

---

Here is the Gmail search phrase I use to find unimportant messages, not from friends, and delete them (usually 99 or 100 at a time).

NOT label:important label:unread in:inbox NOT label:starred

You may want to make a few modifications yourself in case you occasionally received messages not marked as important that include attachments (ie: website backups, quarterly reports, etc).

Hide messages from the search results that have attachments:
NOT has:attachment

NOT from:__________

Gmail - the image cannot be displayed because it contains errors

After sending an image file attachment with Gmail, the recipient said that they could not open the file.

Using Gmail's download link worked for me and I could open up the image.jpg file on my desktop.
However, an error message displayed when clicking on the "view" link.

Here is the error message:

I checked my original file and it opened on my mac without a problem.  Other forums suggested that the error was due to the color profile being in CMYK instead of the web standard sRBG. My image was in sRBG.

The error message was caused by the file extension being wrong.  I had accidentally added a JPG file extension. The file was actually a PSD.  I meant to save it out as a JPG, but clicked on an old file name and forgot to change the save format to JPG.

This online uploader service TrID identified the file type as being a PSD (photoshop document).

Multiple Signatures in Gmail Without Extensions

To create multiple signatures in Gmail, enable the canned responses feature in Gmail labs.
Compose a new message with the signature text, and use the canned responses menu to save it, as seen above.

Source: How To: Have Multiple Signatures in Gmail with No Extensions, Userscripts or Bookmarklets Required