Dobele is the Latvian name. In tsaristic time this place was called ДОБЛЕНЪ (DOBLEN), a transcription of the German name Doblen.
On the picture: Dobele castle. See: Wikipedia
As you see on the map [‘Ostsee-Provinzen’ from Meyers Konv.-Lexicon, 6th ed., about 1905] Dobele is a little place near Mitau, the German name for the Latvian Jelgava. In the postmark on the address-side here below you see the Russian name for Jelgava: МИТАВА (MITAWA), where the card is sent.
In the arrival postmark is indicated ЛИБАВА [LIBAVA], in Latvian Liepāja, in German also known as Libau (address!).
In the arrival postmark is also indicated the governement: Courland: abbreviation of КУРЛЯНДСКАЯ (KURLYANDSKAYA) ГУБЕРНIЯ (GUBERNIYA), Courland Government.
According Baedeker (1914) Dobele was in that time a very small town: “… Doblen, a small town with 2000 inhab., picturesquely situated on the Behrse. It is commanded by the well-preserved ruin of s Castle of the time of the Teutonic Knights, which stands on the top of a hill descending precipitously to the river.”
From: Russia with Teheran, Port Arthur, and Peking : handbook for travellers / by Karl Baedeker. – First English edition published 1914, – This edition reprinted in 1971 and jointly published by David & Charles Newton Abbot and George Allen & Unwin London. – p. 50.
This Baedeker – the English edition of 1914 is also complete on internet::
archive.org/details/russiawithtehera00baed: Russia with Teheran, Port Arthur, and Peking : handbook for travellers (1914). – Translation of 7th German ed. (Leipzig : K. Baedeker, 1912). – With 40 maps and 78 plans. – Maps by: Wagner & Debes’ Geogr. Estab., Leipzig. – Railway map of Russia on back endpaper. – Includes index. – Bibliography: p. lxii-lxiv.