
Since then, a new version of Eudora codenamed Penelope has been built from elements of Mozilla's Thunderbird.
"We are committed to preserving the Eudora user experience and maintaining maximum compatibility for developers and users with Thunderbird," said the developers.
"It is our goal to build a single development community around Thunderbird and Eudora, so that both mailers advance faster than before."
Eudora first appeared in 1988 and quickly became one of the first popular email applications, enjoying its heyday in the early 1990s as it developed over the early days of the internet.
Use of Eudora began to wane in the mid-1990s as the third-party application was muscled out of the market by web-based services such as Hotmail and bundled applications such as Outlook.
Qualcomm purchased Eudora in 1991 and oversaw development of the application for 15 years before turning over the rights to Mozilla in October 2006. All commercial sales on Eudora officially ended on 1 May this year.