I am the first author of a paper that we want to submit (Neuroscience). The journal requirement states that the authors should seek permission from any person that they have acknowledged in the paper. Quoted:
Authors should obtain permission to acknowledge from all those mentioned in the Acknowledgements section.
There is a professor from a different university that had given us some advice on how to use their toolbox and we have mentioned his name in the acknowledgments. I have emailed that professor twice asking permission to acknowledge him but have not heard from him (the second email was roughly 10 days after the first). At this stage, it doesn't look like I will receive a reply. I know that the professor is active on Twitter so I am guessing he has seen the email but not replied.
What can I do at this stage? The journal does not require any "proof" of permission to be uploaded. I really don't want to delay the submission of the paper.
1) Would it be ethical to submit this paper even though I have not received permission from the person being acknowledged?
2) What are my options at this stage? Upload the paper but mention that I did not receive a reply in the cover letter (an editor might reject the paper as it does not then meet the journal guidelines)?