The rock icon was 69 when he died of cancer on Sunday. And before his passing, Bowie began saying goodbye.
Longtime collaborator Brian Eno was in touch with Bowie just a week before his death.
"David's death came as a complete surprise, as did nearly everything else about him. I feel a huge gap now," Eno said in a statement honoring his friend.
"We knew each other for over 40 years ... Over the last few years – with him living in New York and me in London – our connection was by email. We signed off with invented names: some of his were mr showbiz, milton keynes, rhoda borrocks and the duke of ear," Eno continued.
"I received an email from him seven days ago. It was as funny as always, and as surreal, looping through word games and allusions and all the usual stuff we did," Eno added. "It ended with this sentence: 'Thank you for our good times, brian. they will never rot'. And it was signed 'Dawn'. I realize now he was saying goodbye."
And Eno was not Bowie's only friend and collaborator to receive a kind of farewell.
"Two weeks ago, he contacted me by email, and he said, 'Congratulations, I love your book [Rethink/Re-Entry by Paul Gorman]," Derek Boshier – the artist friend who created Bowie's 1979Lodger album art, as well as some stage sets – tells PEOPLE exclusively. "David was such a creative force that working with him sort of imbued that spirit onto you; he passed it on to you."
Bowie's death came just two days after the release of Blackstar. His 25th album, the seven-song set (which featured heavy themes like death and rebirth) was released on his 69th birthday and celebrated with a launch party in Berlin, where Bowie's sound engineer opened up about working with the icon.
"His death was no different from his life – a work of Art. He madeBlackstar for us, his parting gift," Bowie's producer Tony Visconti wrote on Facebook Monday. "I knew for a year this was the way it would be. I wasn't, however, prepared for it. He was an extraordinary man, full of love and life. He will always be with us. For now, it is appropriate to cry."
In a statement to PEOPLE, Visconti added of coproducing the legend's final album: "He sang with powerful energy and determination, his performances were brilliant. He will live forever in our hearts, mine especially."
Bowie made his final public appearance last month at the opening night of Lazarus in New York. The artist cowrote the musical, based on The Man Who Fell to Earth (Bowie starred in the 1976 film).