This Gmail logo was only used for a couple of days before switching to the next one. The 'M' in the logo is off-centered, and there is still 'beta' under the logo, as well.
While Gmail dramatically received a major redesign in Apr. 2013, this was still used on its Basic HTML layout until March 2016 (5 months after Google received a completely new logo), when the logo was finally updated to reflect the search engine's new identity.
In November 2010, Gmail relaunched its frontpage. In the process, they introduced an updated logo which was more in line with Google's recently updated logo. "By Google" was also aligned to the right side below the logo.
Originally introduced on May 30, 2013, this logo first appeared on the mobile application version of Gmail seen on Android version 5.0 Lollipop in 2014, but it made its way to the Google site and the Gmail site itself sometime later, along with the logos of the respective Android versions of other apps by Google (excluding Google Chrome until October 2015). This logo can still be seen regularly.
In July 2020, Google announced a new logo for Gmail. The logo was officially announced on October 6, 2020. As of now, it is used on Google Workspace.
This logo debuted on October 17, 2020 on the website.
Unlike most Google services, Gmail's name does not have Google's name in it. Froogle, now Google Shopping, also didn't have Google's name when it was launched as "Froogle".