You need to next() your pipeline in the filter. It should be:
.filter{
it.out('SOURCE').email.next() == 'someone@email.com'
}
Without the next
you are doing an equality on a Pipeline which will never return true.
As an added suggestion I would recommend you change your emit closure (the second one) on the loop. The emit closure controls the items that escape the pipe. By setting to true
as you have it now it is emitting everything and then you are applying the filter. A bit more compact way to do it would be to make your traversal look like this:
g.v(1).out('ACTIVITIES')
.as('x')
.out('NEXT')
.loop('x'){it.loops <= 10}{it.out('SOURCE').email.next() == 'someone@email.com'}
In this way you handle the filtering in the emit closure as opposed to a separate step of the pipeline.