How do I set a profile picture for a custom email address (which in my case is contact@shivensinha.xyz), i. e., a picture that appears beside the subject on sites like Gmail. For example, if an image is not set, the picture shows the first letter of the name of the sender in Gmail, using Roundcube? Please ask for clarification of the question, if I didn't put my question well, in the comments section. 
How to set a Profile Picture in Roundcube Webmail
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