Laravel mail attachment timeout

I'm using the new Mailing class from Laravel 5.4. Normal (Without attachment) sending does work as expected. But whenever I try to add an PDF attachment it doesn't work:

Maximum execution time of 90 seconds exceeded

Currently using SMTP for gmail. But also doesn't work with Amazon SES (also SMTP).

Really stuck with this, as it doesn't give me clear error messages...

via Chebli Mohamed