A few weeks after releasing Thunderbird 3.0, an overhaul of its open-source e-mail software, Mozilla has issued an early test version of a successor that smooths rough edges and fixes some bugs.

Mozilla Messaging hopes to release Thunderbird 3.1 in early April, a date that reflects a new frequent-release strategy adopted from the better-known Firefox effort at Mozilla. Dan Mosedale, a programmer for the open-source e-mail software, published the date in a Thunderbird schedule draft he announced Thursday. “If we’re lucky, we relabel 3.1RC1 [release candidate 1] [...]