His ministry in Stranraer lasted until 1896, during which time he became a regular contributor to the Original Secession Magazine. Eventually he moved to London to edit The Sunday School Chronicle for two years, before returning to Scotland to minister in Thurso and then Carluke. In London he once walked 35 miles to fulfil a preaching engagement rather than use public transport on the Sabbath. He was a regular speaker at the Keswick Convention, as well as similar gatherings elsewhere: Crieff, Dundee, Glasgow and Portstewart. One report of his Keswick Bible Readings in 1919 said: ‘We saw the Lord Jesus as we had never seen him before - more beautiful and loving; and, like Thomas, we could only fall at his blessed feet in adoration and exclaim, “My Lord and my God”’. An example of one of his sermons can be read here.
The University of Edinburgh conferred upon him an honorary Doctorate of Divinity in 1908. The Scotsman described him as ‘one of the best expository preachers of his day, an exceptionally well-read man, and endowed with a rare, happy saintliness’.
J. D. Douglas comments in the Dictionary of Scottish Church History & Theology that ‘Smellie always had the vision of “a re-united Evangelical and Presbyterian Church in Scotland” and retained cordial relations with those in other churches’. This included J. P. Struthers - RP minister in Whithorn and Greenock. Smellie contributed to an issue of the RP Witness marking the centenary of Struthers’ birth, where he described Struthers as ‘extraordinarily tender and unselfish and generous and hopeful for other people, even the most disappointing and feckless…one of the most Christlike men I have known’.