‘Salute every saint in Christ Jesus.'
The salutation is to ‘every saint (every true believer set apart to God) in Christ Jesus.' As throughout this letter the whole church is seen as being as one on equal terms. Each one is thus to be equally ‘saluted' in Christ Jesus Who is their common LORD. It is all-inclusive. He is confident that they are all welcoming his words, and he sees them all as on the same level.
‘The brothers who are with me salute you.'
He then passes on greetings from ‘the brothers who are with me'. This would indicate those who in one way or another were attendant with him in his imprisonment, and whom he saw especially as ‘his brothers'. As with the Philippian church itself no one person is selected out. All are on ‘common ground' and are equally precious. And there is equal warmth from them to the Philippians as there is from Paul.