Repeated unsolicited emails with no means to unsubscribe oneself (such as the one excerpted below) are SPAM. I like some aspects of the Frontiers journals but your email system has to be changed. I will not submit to or review for your journals until you make some commitment to stopping SPAMMING scientists.
Dear Dr Eisen, The article submission deadline for the Frontiers Research Topic, for which you received a call for participation, is approaching. If you are planning to submit a manuscript and you anticipate any delay beyond the deadline, please inform the Topic Editors and the Frontiers Editorial Office so they can manage the delay. If you have not yet responded to the call for participation or have not yet committed to a submission and you are planning to submit a manuscript, please let us know by responding to this message.PS - the article alerts also have to stop. For F#*$@( sake clean up your act.