Marketo version 1.4307.4 with lightning

Hello,

We have a Marketo Sales Insight version 1.4307.4 installed in Salesforce. The integration user used for the sync is Marketo and profile does not have Lightning access enabled. The rest of the org is all on Lightning. When leads are synced from Marketo to Salesforce, custom process is not sending an email to alias. If i enable the Lightning access for Marketo profile then it works.

My question is, do i have to enable Lightning access in order to send the emails? If i enable Lightning access, is the version 1.4307.4 compatible and do i have to make any changes in configuration settings?